Add Clock page with live DB time and TimeApiClient service

Introduced a new Clock page that displays and updates the current database server time every second by calling a backend API. Added the TimeApiClient service to handle API requests for the server time. Registered TimeApiClient in Program.cs and updated the navigation menu to include a link to the new Clock page. Includes error handling and custom UI styling for the clock display.

DbFirst.API/Controllers/DefaultDashboardController.cs

@@ -0,0 +1,14 @@
+using DevExpress.DashboardAspNetCore;
+using DevExpress.DashboardWeb;
+using Microsoft.AspNetCore.DataProtection;
+
+namespace BlazorDashboardApp.Server
+{
+    public class DefaultDashboardController : DashboardController
+    {
+        public DefaultDashboardController(DashboardConfigurator configurator, IDataProtectionProvider? dataProtectionProvider = null)
+            : base(configurator, dataProtectionProvider)
+        {
+        }
+    }
+}

DbFirst.API/Controllers/LayoutsController.cs

@@ -0,0 +1,94 @@
+using System.Text;
+using DbFirst.Application.Repositories;
+using DbFirst.Domain.Entities;
+using Microsoft.AspNetCore.Mvc;
+
+namespace DbFirst.API.Controllers;
+
+[ApiController]
+[Route("api/[controller]")]
+public class LayoutsController : ControllerBase
+{
+    private readonly ILayoutRepository _repository;
+
+    public LayoutsController(ILayoutRepository repository)
+    {
+        _repository = repository;
+    }
+
+    [HttpGet]
+    public async Task<ActionResult<LayoutDto>> Get([FromQuery] string layoutType, [FromQuery] string layoutKey, [FromQuery] string userName, CancellationToken cancellationToken)
+    {
+        if (string.IsNullOrWhiteSpace(layoutType) || string.IsNullOrWhiteSpace(layoutKey) || string.IsNullOrWhiteSpace(userName))
+        {
+            return BadRequest("layoutType, layoutKey und userName sind erforderlich.");
+        }
+
+        var entity = await _repository.GetAsync(layoutType, layoutKey, userName, cancellationToken);
+        if (entity == null)
+        {
+            return NotFound();
+        }
+
+        return Ok(Map(entity));
+    }
+
+    [HttpPost]
+    public async Task<ActionResult<LayoutDto>> Upsert(LayoutDto dto, CancellationToken cancellationToken)
+    {
+        if (string.IsNullOrWhiteSpace(dto.LayoutType) || string.IsNullOrWhiteSpace(dto.LayoutKey) || string.IsNullOrWhiteSpace(dto.UserName))
+        {
+            return BadRequest("LayoutType, LayoutKey und UserName sind erforderlich.");
+        }
+
+        var data = string.IsNullOrWhiteSpace(dto.LayoutData)
+            ? Array.Empty<byte>()
+            : Encoding.UTF8.GetBytes(dto.LayoutData);
+
+        try
+        {
+            var entity = await _repository.UpsertAsync(dto.LayoutType, dto.LayoutKey, dto.UserName, data, cancellationToken);
+            return Ok(Map(entity));
+        }
+        catch (Exception ex)
+        {
+            var detail = ex.InnerException?.Message ?? ex.Message;
+            return Problem(detail: detail, statusCode: StatusCodes.Status500InternalServerError);
+        }
+    }
+
+    [HttpDelete]
+    public async Task<IActionResult> Delete([FromQuery] string layoutType, [FromQuery] string layoutKey, [FromQuery] string userName, CancellationToken cancellationToken)
+    {
+        if (string.IsNullOrWhiteSpace(layoutType) || string.IsNullOrWhiteSpace(layoutKey) || string.IsNullOrWhiteSpace(userName))
+        {
+            return BadRequest("layoutType, layoutKey und userName sind erforderlich.");
+        }
+
+        var deleted = await _repository.DeleteAsync(layoutType, layoutKey, userName, cancellationToken);
+        return deleted ? NoContent() : NotFound();
+    }
+
+    private static LayoutDto Map(SmfLayout entity)
+    {
+        var layoutData = entity.LayoutData.Length == 0
+            ? string.Empty
+            : Encoding.UTF8.GetString(entity.LayoutData);
+
+        return new LayoutDto
+        {
+            LayoutType = entity.LayoutType,
+            LayoutKey = entity.LayoutKey,
+            UserName = entity.UserName,
+            LayoutData = layoutData
+        };
+    }
+
+    public sealed class LayoutDto
+    {
+        public string LayoutType { get; set; } = string.Empty;
+        public string LayoutKey { get; set; } = string.Empty;
+        public string UserName { get; set; } = string.Empty;
+        public string LayoutData { get; set; } = string.Empty;
+    }
+}

DbFirst.API/Controllers/MassDataController.cs

@@ -0,0 +1,58 @@
+using DbFirst.Application.MassData;
+using DbFirst.Application.MassData.Commands;
+using DbFirst.Application.MassData.Queries;
+using MediatR;
+using Microsoft.AspNetCore.Mvc;
+
+namespace DbFirst.API.Controllers;
+
+[ApiController]
+[Route("api/[controller]")]
+public class MassDataController : ControllerBase
+{
+    private readonly IMediator _mediator;
+
+    public MassDataController(IMediator mediator)
+    {
+        _mediator = mediator;
+    }
+
+    [HttpGet("count")]
+    public async Task<ActionResult<int>> GetCount(CancellationToken cancellationToken)
+    {
+        var count = await _mediator.Send(new GetMassDataCountQuery(), cancellationToken);
+        return Ok(count);
+    }
+
+    [HttpGet]
+    public async Task<ActionResult<IEnumerable<MassDataReadDto>>> GetAll([FromQuery] int? skip, [FromQuery] int? take, CancellationToken cancellationToken)
+    {
+        int? resolvedTake = take;
+        if (resolvedTake is <= 0)
+        {
+            resolvedTake = null;
+        }
+
+        var result = await _mediator.Send(new GetAllMassDataQuery(skip, resolvedTake), cancellationToken);
+        return Ok(result);
+    }
+
+    [HttpGet("{customerName}")]
+    public async Task<ActionResult<MassDataReadDto>> GetByCustomerName(string customerName, CancellationToken cancellationToken)
+    {
+        var result = await _mediator.Send(new GetMassDataByCustomerNameQuery(customerName), cancellationToken);
+        if (result == null)
+        {
+            return NotFound();
+        }
+
+        return Ok(result);
+    }
+
+    [HttpPost("upsert")]
+    public async Task<ActionResult<MassDataReadDto>> Upsert(MassDataWriteDto dto, CancellationToken cancellationToken)
+    {
+        var result = await _mediator.Send(new UpsertMassDataByCustomerNameCommand(dto), cancellationToken);
+        return Ok(result);
+    }
+}

DbFirst.API/Controllers/TimeController.cs

@@ -0,0 +1,28 @@
+using DbFirst.Application.Time.Commands;
+using DbFirst.Domain.Entities;
+using MediatR;
+using Microsoft.AspNetCore.Mvc;
+
+namespace DbFirst.API.Controllers;
+
+[ApiController]
+[Route("api/[controller]")]
+public class TimeController : ControllerBase
+{
+    private readonly IMediator _mediator;
+
+    public TimeController(IMediator mediator)
+    {
+        _mediator = mediator;
+    }
+
+    [HttpPost]
+    public async Task<ActionResult<TimeRecord>> InsertAndGetLast(CancellationToken cancellationToken)
+    {
+        var result = await _mediator.Send(new InsertTimeCommand(), cancellationToken);
+        if (result == null)
+            return NotFound();
+
+        return Ok(result);
+    }
+}

DbFirst.API/Dashboards/DashboardChangeNotifier.cs

@@ -0,0 +1,19 @@
+using DbFirst.API.Hubs;
+using Microsoft.AspNetCore.SignalR;
+
+namespace DbFirst.API.Dashboards;
+
+public class DashboardChangeNotifier : IDashboardChangeNotifier
+{
+    private readonly IHubContext<DashboardsHub> _hubContext;
+
+    public DashboardChangeNotifier(IHubContext<DashboardsHub> hubContext)
+    {
+        _hubContext = hubContext;
+    }
+
+    public void NotifyChanged()
+    {
+        _ = _hubContext.Clients.All.SendAsync("DashboardsChanged");
+    }
+}

DbFirst.API/Dashboards/IDashboardChangeNotifier.cs

@@ -0,0 +1,6 @@
+namespace DbFirst.API.Dashboards;
+
+public interface IDashboardChangeNotifier
+{
+    void NotifyChanged();
+}

DbFirst.API/Dashboards/SqlDashboardStorage.cs

@@ -0,0 +1,138 @@
+using System.Data;
+using System.Text;
+using System.Xml.Linq;
+using DevExpress.DashboardWeb;
+using Microsoft.Data.SqlClient;
+
+namespace DbFirst.API.Dashboards;
+
+public sealed class SqlDashboardStorage : IEditableDashboardStorage
+{
+    private readonly string _connectionString;
+    private readonly string _tableName;
+    private readonly Func<string?>? _userProvider;
+    private readonly IDashboardChangeNotifier? _notifier;
+
+    public SqlDashboardStorage(string connectionString, string tableName = "TBDD_SMF_CONFIG", Func<string?>? userProvider = null, IDashboardChangeNotifier? notifier = null)
+    {
+        _connectionString = connectionString;
+        _tableName = tableName;
+        _userProvider = userProvider;
+        _notifier = notifier;
+    }
+
+    public IEnumerable<DashboardInfo> GetAvailableDashboardsInfo()
+    {
+        var dashboards = new List<DashboardInfo>();
+
+        using var connection = new SqlConnection(_connectionString);
+        using var command = new SqlCommand($"SELECT DashboardId, DashboardName FROM dbo.[{_tableName}] WHERE ACTIVE = 1 ORDER BY DashboardName", connection);
+
+        connection.Open();
+        using var reader = command.ExecuteReader();
+        while (reader.Read())
+        {
+            var id = reader.GetString(0);
+            var name = reader.GetString(1);
+            dashboards.Add(new DashboardInfo { ID = id, Name = name });
+        }
+
+        return dashboards;
+    }
+
+    public XDocument LoadDashboard(string dashboardId)
+    {
+        using var connection = new SqlConnection(_connectionString);
+        using var command = new SqlCommand($"SELECT DashboardData FROM dbo.[{_tableName}] WHERE DashboardId = @Id AND ACTIVE = 1", connection);
+        command.Parameters.Add(new SqlParameter("@Id", SqlDbType.NVarChar, 128) { Value = dashboardId });
+
+        connection.Open();
+        var data = command.ExecuteScalar() as byte[];
+        if (data == null)
+        {
+            throw new ArgumentException($"Dashboard '{dashboardId}' not found.");
+        }
+
+        var xml = Encoding.UTF8.GetString(data);
+        var doc = XDocument.Parse(xml);
+        NormalizeCatalogDateDimensions(doc);
+        return doc;
+    }
+
+    private static void NormalizeCatalogDateDimensions(XDocument doc)
+    {
+        var dateMembers = new HashSet<string>(StringComparer.OrdinalIgnoreCase)
+        {
+            "AddedWhen",
+            "ChangedWhen"
+        };
+
+        foreach (var dimension in doc.Descendants("Dimension"))
+        {
+            var member = dimension.Attribute("DataMember")?.Value;
+            if (member == null || !dateMembers.Contains(member))
+            {
+                continue;
+            }
+
+            var interval = dimension.Attribute("DateTimeGroupInterval")?.Value;
+            if (string.IsNullOrWhiteSpace(interval) || string.Equals(interval, "Year", StringComparison.OrdinalIgnoreCase))
+            {
+                dimension.SetAttributeValue("DateTimeGroupInterval", "DayMonthYear");
+            }
+        }
+    }
+
+    public string AddDashboard(XDocument dashboard, string dashboardName)
+    {
+        var id = string.IsNullOrWhiteSpace(dashboardName)
+            ? Guid.NewGuid().ToString("N")
+            : dashboardName;
+        var payload = Encoding.UTF8.GetBytes(dashboard.ToString(SaveOptions.DisableFormatting));
+        var userName = _userProvider?.Invoke();
+
+        using var connection = new SqlConnection(_connectionString);
+        using var command = new SqlCommand($"INSERT INTO dbo.[{_tableName}] (ACTIVE, DashboardId, DashboardName, DashboardData, ADDED_WHO, ADDED_WHEN) VALUES (1, @Id, @Name, @Data, COALESCE(@User, SUSER_SNAME()), SYSUTCDATETIME())", connection);
+        command.Parameters.Add(new SqlParameter("@Id", SqlDbType.NVarChar, 128) { Value = id });
+        command.Parameters.Add(new SqlParameter("@Name", SqlDbType.NVarChar, 256) { Value = string.IsNullOrWhiteSpace(dashboardName) ? id : dashboardName });
+        command.Parameters.Add(new SqlParameter("@Data", SqlDbType.VarBinary, -1) { Value = payload });
+        command.Parameters.Add(new SqlParameter("@User", SqlDbType.NVarChar, 50) { Value = (object?)userName ?? DBNull.Value });
+
+        connection.Open();
+        command.ExecuteNonQuery();
+        _notifier?.NotifyChanged();
+        return id;
+    }
+
+    public void SaveDashboard(string dashboardId, XDocument dashboard)
+    {
+        var payload = Encoding.UTF8.GetBytes(dashboard.ToString(SaveOptions.DisableFormatting));
+        var userName = _userProvider?.Invoke();
+
+        using var connection = new SqlConnection(_connectionString);
+        using var command = new SqlCommand($"UPDATE dbo.[{_tableName}] SET DashboardData = @Data, CHANGED_WHO = COALESCE(@User, SUSER_SNAME()), CHANGED_WHEN = SYSUTCDATETIME() WHERE DashboardId = @Id", connection);
+        command.Parameters.Add(new SqlParameter("@Id", SqlDbType.NVarChar, 128) { Value = dashboardId });
+        command.Parameters.Add(new SqlParameter("@Data", SqlDbType.VarBinary, -1) { Value = payload });
+        command.Parameters.Add(new SqlParameter("@User", SqlDbType.NVarChar, 50) { Value = (object?)userName ?? DBNull.Value });
+
+        connection.Open();
+        var rows = command.ExecuteNonQuery();
+        if (rows == 0)
+        {
+            throw new ArgumentException($"Dashboard '{dashboardId}' not found.");
+        }
+
+        _notifier?.NotifyChanged();
+    }
+
+    public void DeleteDashboard(string dashboardId)
+    {
+        using var connection = new SqlConnection(_connectionString);
+        using var command = new SqlCommand($"DELETE FROM dbo.[{_tableName}] WHERE DashboardId = @Id", connection);
+        command.Parameters.Add(new SqlParameter("@Id", SqlDbType.NVarChar, 128) { Value = dashboardId });
+
+        connection.Open();
+        command.ExecuteNonQuery();
+        _notifier?.NotifyChanged();
+    }
+}

DbFirst.API/Data/Dashboards/CatalogsGrid.xml

@@ -0,0 +1,52 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Dashboard CurrencyCulture="de-DE" RequestParameters="false">
+  <Title Text="Catalogs (Dashboard Grid)" />
+  <DataSources>
+    <JsonDataSource Name="Catalogs (API)" ComponentName="catalogsDataSource">
+      <Source SourceType="DevExpress.DataAccess.Json.UriJsonSource" Uri="https://localhost:7204/api/catalogs" />
+    </JsonDataSource>
+  </DataSources>
+  <Items>
+    <Grid ComponentName="gridDashboardItem1" Name="Catalogs" DataSource="catalogsDataSource">
+      <DataItems>
+        <Dimension DataMember="Guid" DefaultId="DataItem0" />
+        <Dimension DataMember="CatTitle" DefaultId="DataItem1" />
+        <Dimension DataMember="CatString" DefaultId="DataItem2" />
+        <Dimension DataMember="AddedWho" DefaultId="DataItem3" />
+        <Dimension DataMember="AddedWhen" DefaultId="DataItem4" />
+        <Dimension DataMember="ChangedWho" DefaultId="DataItem5" />
+        <Dimension DataMember="ChangedWhen" DefaultId="DataItem6" />
+      </DataItems>
+      <GridColumns>
+        <GridDimensionColumn Name="Id">
+          <Dimension DefaultId="DataItem0" />
+        </GridDimensionColumn>
+        <GridDimensionColumn Name="Titel">
+          <Dimension DefaultId="DataItem1" />
+        </GridDimensionColumn>
+        <GridDimensionColumn Name="String">
+          <Dimension DefaultId="DataItem2" />
+        </GridDimensionColumn>
+        <GridDimensionColumn Name="Angelegt von">
+          <Dimension DefaultId="DataItem3" />
+        </GridDimensionColumn>
+        <GridDimensionColumn Name="Angelegt am">
+          <Dimension DefaultId="DataItem4" />
+        </GridDimensionColumn>
+        <GridDimensionColumn Name="Geändert von">
+          <Dimension DefaultId="DataItem5" />
+        </GridDimensionColumn>
+        <GridDimensionColumn Name="Geändert am">
+          <Dimension DefaultId="DataItem6" />
+        </GridDimensionColumn>
+      </GridColumns>
+      <GridOptions />
+      <ColumnFilterOptions />
+    </Grid>
+  </Items>
+  <LayoutTree>
+    <LayoutGroup Orientation="Vertical">
+      <LayoutItem DashboardItem="gridDashboardItem1" />
+    </LayoutGroup>
+  </LayoutTree>
+</Dashboard>

DbFirst.API/Data/Dashboards/DashboardStorage.sql

@@ -0,0 +1,17 @@
+CREATE TABLE dbo.TBDD_SMF_CONFIG (
+    [GUID] [bigint] IDENTITY(1,1) NOT NULL,
+    [ACTIVE] [bit] NOT NULL,
+    DashboardId NVARCHAR(128) NOT NULL,
+    DashboardName NVARCHAR(256) NOT NULL,
+    DashboardData VARBINARY(MAX) NOT NULL,
+    --- INSERT YOUR COLUMNS HERE ---
+    [ADDED_WHO] [nvarchar](50) NOT NULL,
+    [ADDED_WHEN] [datetime] NOT NULL,
+    [CHANGED_WHO] [nvarchar](50) NULL,
+    [CHANGED_WHEN] [datetime] NULL,
+ CONSTRAINT [PK_TBDD_SMF_CONFIG_DashboardStorage] PRIMARY KEY CLUSTERED 
+(
+    [GUID] ASC
+)WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = ON, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON, FILLFACTOR = 80) ON [PRIMARY]
+) ON [PRIMARY]
+GO

DbFirst.API/Data/Dashboards/DefaultDashboard.xml

@@ -0,0 +1,55 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Dashboard CurrencyCulture="de-DE" RequestParameters="false">
+  <Title Text="Default Dashboard" />
+  <DataSources>
+    <JsonDataSource Name="JSON Data Source (URL)" RootElement="Customers" ComponentName="jsonDataSource1">
+      <Source SourceType="DevExpress.DataAccess.Json.UriJsonSource" Uri="https://raw.githubusercontent.com/DevExpress-Examples/DataSources/master/JSON/customers.json" />
+    </JsonDataSource>
+    <JsonDataSource Name="Catalogs (API)" ComponentName="catalogsDataSource">
+      <Source SourceType="DevExpress.DataAccess.Json.UriJsonSource" Uri="https://localhost:7204/api/catalogs" />
+    </JsonDataSource>
+  </DataSources>
+  <Items>
+    <Grid ComponentName="gridDashboardItem2" Name="Grid 2" DataSource="catalogsDataSource">
+      <DataItems>
+        <Measure DataMember="guid" DefaultId="DataItem0" />
+        <Dimension DataMember="catTitle" DefaultId="DataItem1" />
+        <Dimension DataMember="catString" DefaultId="DataItem2" />
+        <Dimension DataMember="addedWhen" DefaultId="DataItem3" />
+        <Dimension DataMember="addedWho" DefaultId="DataItem4" />
+        <Dimension DataMember="changedWhen" DefaultId="DataItem5" />
+        <Dimension DataMember="changedWho" DefaultId="DataItem6" />
+      </DataItems>
+      <GridColumns>
+        <GridMeasureColumn>
+          <Measure DefaultId="DataItem0" />
+        </GridMeasureColumn>
+        <GridDimensionColumn>
+          <Dimension DefaultId="DataItem1" />
+        </GridDimensionColumn>
+        <GridDimensionColumn>
+          <Dimension DefaultId="DataItem2" />
+        </GridDimensionColumn>
+        <GridDimensionColumn>
+          <Dimension DefaultId="DataItem3" />
+        </GridDimensionColumn>
+        <GridDimensionColumn>
+          <Dimension DefaultId="DataItem4" />
+        </GridDimensionColumn>
+        <GridDimensionColumn>
+          <Dimension DefaultId="DataItem5" />
+        </GridDimensionColumn>
+        <GridDimensionColumn>
+          <Dimension DefaultId="DataItem6" />
+        </GridDimensionColumn>
+      </GridColumns>
+      <GridOptions />
+      <ColumnFilterOptions />
+    </Grid>
+  </Items>
+  <LayoutTree>
+    <LayoutGroup>
+      <LayoutItem DashboardItem="gridDashboardItem2" />
+    </LayoutGroup>
+  </LayoutTree>
+</Dashboard>

DbFirst.API/DbFirst.API.csproj

@@ -9,6 +9,7 @@
   <ItemGroup>
     <PackageReference Include="AutoMapper" Version="12.0.1" />
     <PackageReference Include="AutoMapper.Extensions.Microsoft.DependencyInjection" Version="12.0.1" />
+    <PackageReference Include="DevExpress.AspNetCore.Dashboard" Version="25.2.3" />
     <PackageReference Include="Microsoft.EntityFrameworkCore" Version="8.0.22" />
     <PackageReference Include="Microsoft.EntityFrameworkCore.SqlServer" Version="8.0.22" />
     <PackageReference Include="Microsoft.EntityFrameworkCore.Tools" Version="8.0.22">

DbFirst.API/Hubs/DashboardsHub.cs

@@ -0,0 +1,7 @@
+using Microsoft.AspNetCore.SignalR;
+
+namespace DbFirst.API.Hubs;
+
+public class DashboardsHub : Hub
+{
+}

DbFirst.API/Program.cs

@@ -1,8 +1,18 @@
 using DbFirst.API.Middleware;
+using DbFirst.API.Dashboards;
+using DbFirst.API.Hubs;
 using DbFirst.Application;
 using DbFirst.Application.Repositories;
+using DbFirst.Domain;
+using DbFirst.Domain.Entities;
 using DbFirst.Infrastructure;
 using DbFirst.Infrastructure.Repositories;
+using DevExpress.AspNetCore;
+using DevExpress.DashboardAspNetCore;
+using DevExpress.DashboardCommon;
+using DevExpress.DashboardWeb;
+using DevExpress.DataAccess.Json;
+using System.Xml.Linq;
 
 var builder = WebApplication.CreateBuilder(args);
 
@@ -15,10 +25,10 @@ builder.Services.AddSwaggerGen();
 // In any case, dont let them to free to use without cors. if there is no origin specified, block all.
 // In development you can keep it easy.
 builder.Services.AddCors(options =>
-{    
+{
     options.AddDefaultPolicy(policy =>
     {
-        if(builder.Environment.IsDevelopment())
+        if (builder.Environment.IsDevelopment())
         {
             policy.AllowAnyOrigin()
                   .AllowAnyHeader()
@@ -26,10 +36,14 @@ builder.Services.AddCors(options =>
         }
         else
         {
-            var origins = builder.Configuration.GetSection("Cors:AllowedOrigins").Get<string[]>() ?? [];
-            policy.WithOrigins(origins)
-                  .AllowAnyHeader()
-                  .AllowAnyMethod();
+            var origins = builder.Configuration.GetSection("Cors:AllowedOrigins").Get<string[]>() ?? Array.Empty<string>();
+            if (origins.Length > 0)
+            {
+                policy.WithOrigins(origins)
+                      .AllowAnyHeader()
+                      .AllowAnyMethod();
+            }
+            // if no origins configured, deny all by leaving policy without allowances
         }
     });
 });
@@ -38,6 +52,98 @@ builder.Services.AddInfrastructure(builder.Configuration);
 builder.Services.AddApplication();
 
 builder.Services.AddScoped<ICatalogRepository, CatalogRepository>();
+builder.Services.AddScoped<IMassDataRepository, MassDataRepository>();
+builder.Services.AddScoped<ILayoutRepository, LayoutRepository>();
+builder.Services.AddScoped<ITimeRepository, TimeRepository>();
+
+builder.Services.AddDevExpressControls();
+builder.Services.AddSignalR();
+builder.Services.AddSingleton<IDashboardChangeNotifier, DashboardChangeNotifier>();
+builder.Services.AddScoped<DashboardConfigurator>((IServiceProvider serviceProvider) => {
+    var dashboardsPath = Path.Combine(builder.Environment.ContentRootPath, "Data", "Dashboards");
+    Directory.CreateDirectory(dashboardsPath);
+
+    var defaultDashboardPath = Path.Combine(dashboardsPath, "DefaultDashboard.xml");
+    if (!File.Exists(defaultDashboardPath))
+    {
+        var defaultDashboard = new Dashboard();
+        defaultDashboard.Title.Text = "Default Dashboard";
+        defaultDashboard.SaveToXml(defaultDashboardPath);
+    }
+
+    var dashboardBaseUrl = builder.Configuration["Dashboard:BaseUrl"]
+        ?? builder.Configuration["ApiBaseUrl"]
+        ?? builder.Configuration["ASPNETCORE_URLS"]?.Split(';', StringSplitOptions.RemoveEmptyEntries).FirstOrDefault()
+        ?? "https://localhost:7204";
+
+    dashboardBaseUrl = dashboardBaseUrl.TrimEnd('/');
+
+    var catalogsGridDashboardPath = Path.Combine(dashboardsPath, "CatalogsGrid.xml");
+    if (!File.Exists(catalogsGridDashboardPath))
+    {
+        var dashboard = new Dashboard();
+        dashboard.Title.Text = "Catalogs (Dashboard Grid)";
+
+        var catalogDataSource = new DashboardJsonDataSource("Catalogs (API)")
+        {
+            ComponentName = "catalogsDataSource",
+            JsonSource = new UriJsonSource(new Uri($"{dashboardBaseUrl}/api/catalogs"))
+        };
+
+        dashboard.DataSources.Add(catalogDataSource);
+
+        var grid = new GridDashboardItem
+        {
+            DataSource = catalogDataSource,
+            Name = "Catalogs"
+        };
+
+        grid.Columns.Add(new GridDimensionColumn(new Dimension(nameof(VwmyCatalog.Guid))) { Name = "Id" });
+        grid.Columns.Add(new GridDimensionColumn(new Dimension(nameof(VwmyCatalog.CatTitle))) { Name = "Titel" });
+        grid.Columns.Add(new GridDimensionColumn(new Dimension(nameof(VwmyCatalog.CatString))) { Name = "String" });
+        grid.Columns.Add(new GridDimensionColumn(new Dimension(nameof(VwmyCatalog.AddedWho))) { Name = "Angelegt von" });
+        grid.Columns.Add(new GridDimensionColumn(new Dimension(nameof(VwmyCatalog.AddedWhen))) { Name = "Angelegt am" });
+        grid.Columns.Add(new GridDimensionColumn(new Dimension(nameof(VwmyCatalog.ChangedWho))) { Name = "Geändert von" });
+        grid.Columns.Add(new GridDimensionColumn(new Dimension(nameof(VwmyCatalog.ChangedWhen))) { Name = "Geändert am" });
+
+        dashboard.Items.Add(grid);
+
+        var layoutGroup = new DashboardLayoutGroup { Orientation = DashboardLayoutGroupOrientation.Vertical };
+        layoutGroup.ChildNodes.Add(new DashboardLayoutItem(grid));
+        dashboard.LayoutRoot = layoutGroup;
+
+        dashboard.SaveToXml(catalogsGridDashboardPath);
+    }
+
+    DashboardConfigurator configurator = new DashboardConfigurator();
+
+    var connectionString = builder.Configuration.GetConnectionString("DefaultConnection") ?? string.Empty;
+    var notifier = serviceProvider.GetRequiredService<IDashboardChangeNotifier>();
+    var dashboardStorage = new SqlDashboardStorage(connectionString, "TBDD_SMF_CONFIG", notifier: notifier);
+    configurator.SetDashboardStorage(dashboardStorage);
+
+    DataSourceInMemoryStorage dataSourceStorage = new DataSourceInMemoryStorage();
+    DashboardJsonDataSource jsonDataSourceUrl = new DashboardJsonDataSource("JSON Data Source (URL)");
+    jsonDataSourceUrl.JsonSource = new UriJsonSource(
+            new Uri("https://raw.githubusercontent.com/DevExpress-Examples/DataSources/master/JSON/customers.json"));
+    jsonDataSourceUrl.RootElement = "Customers";
+    dataSourceStorage.RegisterDataSource("jsonDataSourceUrl", jsonDataSourceUrl.SaveToXml());
+
+    var catalogsJsonDataSource = new DashboardJsonDataSource("Catalogs (API)")
+    {
+        ComponentName = "catalogsDataSource",
+        JsonSource = new UriJsonSource(new Uri($"{dashboardBaseUrl}/api/catalogs"))
+    };
+    dataSourceStorage.RegisterDataSource(catalogsJsonDataSource.ComponentName, catalogsJsonDataSource.SaveToXml());
+    dataSourceStorage.RegisterDataSource(catalogsJsonDataSource.Name, catalogsJsonDataSource.SaveToXml());
+
+    configurator.SetDataSourceStorage(dataSourceStorage);
+
+    EnsureDashboardInStorage(dashboardStorage, "DefaultDashboard", defaultDashboardPath);
+    EnsureDashboardInStorage(dashboardStorage, "CatalogsGrid", catalogsGridDashboardPath);
+
+    return configurator;
+});
 
 var app = builder.Build();
 
@@ -50,10 +156,25 @@ if (app.Environment.IsDevelopment())
 
 app.UseMiddleware<ExceptionHandlingMiddleware>();
 
+app.UseDevExpressControls();
 app.UseHttpsRedirection();
 app.UseCors();
 app.UseAuthorization();
 
+app.MapDashboardRoute("api/dashboard", "DefaultDashboard");
+app.MapHub<DashboardsHub>("/hubs/dashboards");
 app.MapControllers();
 
 app.Run();
+
+static void EnsureDashboardInStorage(IEditableDashboardStorage storage, string id, string filePath)
+{
+    var exists = storage.GetAvailableDashboardsInfo().Any(info => string.Equals(info.ID, id, StringComparison.OrdinalIgnoreCase));
+    if (exists || !File.Exists(filePath))
+    {
+        return;
+    }
+
+    var doc = XDocument.Load(filePath);
+    storage.AddDashboard(doc, id);
+}

DbFirst.API/appsettings.json

@@ -1,6 +1,10 @@
 {
   "ConnectionStrings": {
-    "DefaultConnection": "Server=SDD-VMP04-SQL17\\DD_DEVELOP01;Database=DD_ECM;User Id=sa;Password=dd;TrustServerCertificate=True;"
+    "DefaultConnection": "Server=SDD-VMP04-SQL17\\DD_DEVELOP01;Database=DD_ECM;User Id=sa;Password=dd;TrustServerCertificate=True;",
+    "MassDataConnection": "Server=SDD-VMP04-SQL19\\DD_DEVELOP01;Database=DD_ECM;User Id=sa;Password=dd;TrustServerCertificate=True;"
+  },
+  "Dashboard": {
+    "BaseUrl": "https://localhost:7204"
   },
   "Cors": {
     "AllowedOrigins": [

DbFirst.Application/MassData/Commands/UpsertMassDataByCustomerNameCommand.cs

@@ -0,0 +1,5 @@
+using MediatR;
+
+namespace DbFirst.Application.MassData.Commands;
+
+public record UpsertMassDataByCustomerNameCommand(MassDataWriteDto Dto) : IRequest<MassDataReadDto>;

DbFirst.Application/MassData/Commands/UpsertMassDataByCustomerNameHandler.cs

@@ -0,0 +1,24 @@
+using AutoMapper;
+using DbFirst.Application.Repositories;
+using MediatR;
+
+namespace DbFirst.Application.MassData.Commands;
+
+public class UpsertMassDataByCustomerNameHandler : IRequestHandler<UpsertMassDataByCustomerNameCommand, MassDataReadDto>
+{
+    private readonly IMassDataRepository _repository;
+    private readonly IMapper _mapper;
+
+    public UpsertMassDataByCustomerNameHandler(IMassDataRepository repository, IMapper mapper)
+    {
+        _repository = repository;
+        _mapper = mapper;
+    }
+
+    public async Task<MassDataReadDto> Handle(UpsertMassDataByCustomerNameCommand request, CancellationToken cancellationToken)
+    {
+        var dto = request.Dto;
+        var updated = await _repository.UpsertByCustomerNameAsync(dto.CustomerName, dto.Amount, dto.StatusFlag, dto.Category, cancellationToken);
+        return _mapper.Map<MassDataReadDto>(updated);
+    }
+}

DbFirst.Application/MassData/MassDataProfile.cs

@@ -0,0 +1,12 @@
+using AutoMapper;
+using DbFirst.Domain.Entities;
+
+namespace DbFirst.Application.MassData;
+
+public class MassDataProfile : Profile
+{
+    public MassDataProfile()
+    {
+        CreateMap<Massdata, MassDataReadDto>();
+    }
+}

DbFirst.Application/MassData/MassDataReadDto.cs

@@ -0,0 +1,12 @@
+namespace DbFirst.Application.MassData;
+
+public class MassDataReadDto
+{
+    public int Id { get; set; }
+    public string CustomerName { get; set; } = string.Empty;
+    public decimal Amount { get; set; }
+    public string Category { get; set; } = string.Empty;
+    public bool StatusFlag { get; set; }
+    public DateTime AddedWhen { get; set; }
+    public DateTime? ChangedWhen { get; set; }
+}

DbFirst.Application/MassData/MassDataWriteDto.cs

@@ -0,0 +1,9 @@
+namespace DbFirst.Application.MassData;
+
+public class MassDataWriteDto
+{
+    public string CustomerName { get; set; } = string.Empty;
+    public decimal Amount { get; set; }
+    public string Category { get; set; } = string.Empty;
+    public bool StatusFlag { get; set; }
+}

DbFirst.Application/MassData/Queries/GetAllMassDataHandler.cs

@@ -0,0 +1,23 @@
+using AutoMapper;
+using DbFirst.Application.Repositories;
+using MediatR;
+
+namespace DbFirst.Application.MassData.Queries;
+
+public class GetAllMassDataHandler : IRequestHandler<GetAllMassDataQuery, List<MassDataReadDto>>
+{
+    private readonly IMassDataRepository _repository;
+    private readonly IMapper _mapper;
+
+    public GetAllMassDataHandler(IMassDataRepository repository, IMapper mapper)
+    {
+        _repository = repository;
+        _mapper = mapper;
+    }
+
+    public async Task<List<MassDataReadDto>> Handle(GetAllMassDataQuery request, CancellationToken cancellationToken)
+    {
+        var items = await _repository.GetAllAsync(request.Skip, request.Take, cancellationToken);
+        return _mapper.Map<List<MassDataReadDto>>(items);
+    }
+}

DbFirst.Application/MassData/Queries/GetAllMassDataQuery.cs

@@ -0,0 +1,5 @@
+using MediatR;
+
+namespace DbFirst.Application.MassData.Queries;
+
+public record GetAllMassDataQuery(int? Skip, int? Take) : IRequest<List<MassDataReadDto>>;

DbFirst.Application/MassData/Queries/GetMassDataByCustomerNameHandler.cs

@@ -0,0 +1,23 @@
+using AutoMapper;
+using DbFirst.Application.Repositories;
+using MediatR;
+
+namespace DbFirst.Application.MassData.Queries;
+
+public class GetMassDataByCustomerNameHandler : IRequestHandler<GetMassDataByCustomerNameQuery, MassDataReadDto?>
+{
+    private readonly IMassDataRepository _repository;
+    private readonly IMapper _mapper;
+
+    public GetMassDataByCustomerNameHandler(IMassDataRepository repository, IMapper mapper)
+    {
+        _repository = repository;
+        _mapper = mapper;
+    }
+
+    public async Task<MassDataReadDto?> Handle(GetMassDataByCustomerNameQuery request, CancellationToken cancellationToken)
+    {
+        var item = await _repository.GetByCustomerNameAsync(request.CustomerName, cancellationToken);
+        return item == null ? null : _mapper.Map<MassDataReadDto>(item);
+    }
+}

DbFirst.Application/MassData/Queries/GetMassDataByCustomerNameQuery.cs

@@ -0,0 +1,5 @@
+using MediatR;
+
+namespace DbFirst.Application.MassData.Queries;
+
+public record GetMassDataByCustomerNameQuery(string CustomerName) : IRequest<MassDataReadDto?>;

DbFirst.Application/MassData/Queries/GetMassDataCountHandler.cs

@@ -0,0 +1,19 @@
+using DbFirst.Application.Repositories;
+using MediatR;
+
+namespace DbFirst.Application.MassData.Queries;
+
+public class GetMassDataCountHandler : IRequestHandler<GetMassDataCountQuery, int>
+{
+    private readonly IMassDataRepository _repository;
+
+    public GetMassDataCountHandler(IMassDataRepository repository)
+    {
+        _repository = repository;
+    }
+
+    public async Task<int> Handle(GetMassDataCountQuery request, CancellationToken cancellationToken)
+    {
+        return await _repository.GetCountAsync(cancellationToken);
+    }
+}

DbFirst.Application/MassData/Queries/GetMassDataCountQuery.cs

@@ -0,0 +1,5 @@
+using MediatR;
+
+namespace DbFirst.Application.MassData.Queries;
+
+public record GetMassDataCountQuery : IRequest<int>;

DbFirst.Application/Repositories/ILayoutRepository.cs

@@ -0,0 +1,10 @@
+using DbFirst.Domain.Entities;
+
+namespace DbFirst.Application.Repositories;
+
+public interface ILayoutRepository
+{
+    Task<SmfLayout?> GetAsync(string layoutType, string layoutKey, string userName, CancellationToken cancellationToken = default);
+    Task<SmfLayout> UpsertAsync(string layoutType, string layoutKey, string userName, byte[] layoutData, CancellationToken cancellationToken = default);
+    Task<bool> DeleteAsync(string layoutType, string layoutKey, string userName, CancellationToken cancellationToken = default);
+}

DbFirst.Application/Repositories/IMassDataRepository.cs

@@ -0,0 +1,11 @@
+using DbFirst.Domain.Entities;
+
+namespace DbFirst.Application.Repositories;
+
+public interface IMassDataRepository
+{
+    Task<int> GetCountAsync(CancellationToken cancellationToken = default);
+    Task<List<Massdata>> GetAllAsync(int? skip = null, int? take = null, CancellationToken cancellationToken = default);
+    Task<Massdata?> GetByCustomerNameAsync(string customerName, CancellationToken cancellationToken = default);
+    Task<Massdata> UpsertByCustomerNameAsync(string customerName, decimal amount, bool statusFlag, string category, CancellationToken cancellationToken = default);
+}

DbFirst.Application/Repositories/ITimeRepository.cs

@@ -0,0 +1,9 @@
+using DbFirst.Domain.Entities;
+
+namespace DbFirst.Application.Repositories;
+
+public interface ITimeRepository
+{
+    Task InsertAsync(CancellationToken cancellationToken = default);
+    Task<TimeRecord?> GetLastAsync(CancellationToken cancellationToken = default);
+}

DbFirst.Application/Time/Commands/InsertTimeCommand.cs

@@ -0,0 +1,6 @@
+using DbFirst.Domain.Entities;
+using MediatR;
+
+namespace DbFirst.Application.Time.Commands;
+
+public record InsertTimeCommand : IRequest<TimeRecord?>;

DbFirst.Application/Time/Commands/InsertTimeHandler.cs

@@ -0,0 +1,21 @@
+using DbFirst.Application.Repositories;
+using DbFirst.Domain.Entities;
+using MediatR;
+
+namespace DbFirst.Application.Time.Commands;
+
+public class InsertTimeHandler : IRequestHandler<InsertTimeCommand, TimeRecord?>
+{
+    private readonly ITimeRepository _repository;
+
+    public InsertTimeHandler(ITimeRepository repository)
+    {
+        _repository = repository;
+    }
+
+    public async Task<TimeRecord?> Handle(InsertTimeCommand request, CancellationToken cancellationToken)
+    {
+        await _repository.InsertAsync(cancellationToken);
+        return await _repository.GetLastAsync(cancellationToken);
+    }
+}

DbFirst.BlazorWasm/App.razor

@@ -1,12 +0,0 @@
-<Router AppAssembly="@typeof(App).Assembly">
-    <Found Context="routeData">
-        <RouteView RouteData="@routeData" DefaultLayout="@typeof(MainLayout)" />
-        <FocusOnNavigate RouteData="@routeData" Selector="h1" />
-    </Found>
-    <NotFound>
-        <PageTitle>Not found</PageTitle>
-        <LayoutView Layout="@typeof(MainLayout)">
-            <p role="alert">Sorry, there's nothing at this address.</p>
-        </LayoutView>
-    </NotFound>
-</Router>

DbFirst.BlazorWasm/DbFirst.BlazorWasm.csproj

@@ -1,18 +0,0 @@
-<Project Sdk="Microsoft.NET.Sdk.BlazorWebAssembly">
-
-  <PropertyGroup>
-    <TargetFramework>net8.0</TargetFramework>
-    <Nullable>enable</Nullable>
-    <ImplicitUsings>enable</ImplicitUsings>
-  </PropertyGroup>
-
-  <ItemGroup>
-    <PackageReference Include="Microsoft.AspNetCore.Components.WebAssembly" Version="8.0.22" />
-    <PackageReference Include="Microsoft.AspNetCore.Components.WebAssembly.DevServer" Version="8.0.22" PrivateAssets="all" />
-  </ItemGroup>
-
-  <ItemGroup>
-    <Folder Include="wwwroot\sample-data\" />
-  </ItemGroup>
-
-</Project>

DbFirst.BlazorWasm/Layout/MainLayout.razor

@@ -1,16 +0,0 @@
-@inherits LayoutComponentBase
-<div class="page">
-    <div class="sidebar">
-        <NavMenu />
-    </div>
-
-    <main>
-        <div class="top-row px-4">
-            <a href="https://learn.microsoft.com/aspnet/core/" target="_blank">About</a>
-        </div>
-
-        <article class="content px-4">
-            @Body
-        </article>
-    </main>
-</div>

DbFirst.BlazorWasm/Layout/NavMenu.razor

@@ -1,34 +0,0 @@
-<div class="top-row ps-3 navbar navbar-dark">
-    <div class="container-fluid">
-        <a class="navbar-brand" href="">DbFirst.BlazorWasm</a>
-        <button title="Navigation menu" class="navbar-toggler" @onclick="ToggleNavMenu">
-            <span class="navbar-toggler-icon"></span>
-        </button>
-    </div>
-</div>
-
-<div class="@NavMenuCssClass nav-scrollable" @onclick="ToggleNavMenu">
-    <nav class="flex-column">
-        <div class="nav-item px-3">
-            <NavLink class="nav-link" href="" Match="NavLinkMatch.All">
-                <span class="bi bi-house-door-fill-nav-menu" aria-hidden="true"></span> Home
-            </NavLink>
-        </div>
-        <div class="nav-item px-3">
-            <NavLink class="nav-link" href="catalogs">
-                <span class="bi bi-collection-nav-menu" aria-hidden="true"></span> Catalogs
-            </NavLink>
-        </div>
-    </nav>
-</div>
-
-@code {
-    private bool collapseNavMenu = true;
-
-    private string? NavMenuCssClass => collapseNavMenu ? "collapse" : null;
-
-    private void ToggleNavMenu()
-    {
-        collapseNavMenu = !collapseNavMenu;
-    }
-}

DbFirst.BlazorWasm/Models/CatalogReadDto.cs

@@ -1,12 +0,0 @@
-namespace DbFirst.BlazorWasm.Models;
-
-public class CatalogReadDto
-{
-    public int Guid { get; set; }
-    public string CatTitle { get; set; } = string.Empty;
-    public string CatString { get; set; } = string.Empty;
-    public string AddedWho { get; set; } = string.Empty;
-    public DateTime AddedWhen { get; set; }
-    public string? ChangedWho { get; set; }
-    public DateTime? ChangedWhen { get; set; }
-}

DbFirst.BlazorWasm/Pages/Catalogs.razor

@@ -1,226 +0,0 @@
-@page "/catalogs"
-@inject CatalogApiClient Api
-
-<PageTitle>Catalogs</PageTitle>
-
-<h1>Catalogs</h1>
-
-@if (!string.IsNullOrWhiteSpace(errorMessage))
-{
-    <div class="alert alert-danger" role="alert">@errorMessage</div>
-}
-else if (!string.IsNullOrWhiteSpace(infoMessage))
-{
-    <div class="alert alert-success" role="alert">@infoMessage</div>
-}
-
-<div class="mb-3">
-    <button class="btn btn-primary" @onclick="StartCreate">Neuen Eintrag anlegen</button>
-</div>
-
-@if (showForm)
-{
-    <EditForm Model="formModel" OnValidSubmit="HandleSubmit">
-        <div class="row g-3">
-            <div class="col-md-6">
-                <label class="form-label">Titel</label>
-                <InputText class="form-control" @bind-Value="formModel.CatTitle" disabled="@(isEditing && formModel.UpdateProcedure == 0)" />
-            </div>
-            <div class="col-md-6">
-                <label class="form-label">Kennung</label>
-                <InputText class="form-control" @bind-Value="formModel.CatString" />
-            </div>
-        </div>
-
-        @if (isEditing)
-        {
-            <div class="row g-3 mt-2">
-                <div class="col-md-6">
-                    <label class="form-label">Update-Prozedur</label>
-                    <InputSelect class="form-control" @bind-Value="formModel.UpdateProcedure">
-                        <option value="0">PRTBMY_CATALOG_UPDATE</option>
-                        <option value="1">PRTBMY_CATALOG_SAVE</option>
-                    </InputSelect>
-                </div>
-            </div>
-        }
-
-        <div class="mt-3 d-flex gap-2">
-            <button type="submit" class="btn btn-success">@((isEditing ? "Speichern" : "Anlegen"))</button>
-            <button type="button" class="btn btn-secondary" @onclick="CancelEdit">Abbrechen</button>
-        </div>
-    </EditForm>
-}
-
-@if (isLoading)
-{
-    <p><em>Lade Daten...</em></p>
-}
-else if (items.Count == 0)
-{
-    <p>Keine Einträge vorhanden.</p>
-}
-else
-{
-    <table class="table table-striped">
-        <thead>
-            <tr>
-                <th>Id</th>
-                <th>Titel</th>
-                <th>String</th>
-                <th>Angelegt von</th>
-                <th>Angelegt am</th>
-                <th>Geändert von</th>
-                <th>Geändert am</th>
-                <th></th>
-            </tr>
-        </thead>
-        <tbody>
-            @foreach (var item in items)
-            {
-                <tr>
-                    <td>@item.Guid</td>
-                    <td>@item.CatTitle</td>
-                    <td>@item.CatString</td>
-                    <td>@item.AddedWho</td>
-                    <td>@item.AddedWhen.ToString("g")</td>
-                    <td>@item.ChangedWho</td>
-                    <td>@(item.ChangedWhen.HasValue ? item.ChangedWhen.Value.ToString("g") : string.Empty)</td>
-                    <td class="text-end">
-                        <button class="btn btn-sm btn-outline-primary me-2" @onclick="(() => StartEdit(item))">Bearbeiten</button>
-                        <button class="btn btn-sm btn-outline-danger" @onclick="(() => DeleteCatalog(item.Guid))">Löschen</button>
-                    </td>
-                </tr>
-            }
-        </tbody>
-    </table>
-}
-
-@code {
-    private List<CatalogReadDto> items = new();
-    private CatalogWriteDto formModel = new();
-    private int editingId;
-    private bool isLoading;
-    private bool isEditing;
-    private bool showForm;
-    private string? errorMessage;
-    private string? infoMessage;
-
-    protected override async Task OnInitializedAsync()
-    {
-        await LoadCatalogs();
-    }
-
-    private async Task LoadCatalogs()
-    {
-        isLoading = true;
-        errorMessage = null;
-        try
-        {
-            items = await Api.GetAllAsync();
-        }
-        catch (Exception ex)
-        {
-            errorMessage = $"Kataloge konnten nicht geladen werden: {ex.Message}";
-        }
-        finally
-        {
-            isLoading = false;
-            StateHasChanged();
-        }
-    }
-
-    private void StartCreate()
-    {
-        formModel = new CatalogWriteDto();
-        editingId = 0;
-        isEditing = false;
-        showForm = true;
-        infoMessage = null;
-        errorMessage = null;
-    }
-
-    private void StartEdit(CatalogReadDto item)
-    {
-        formModel = new CatalogWriteDto
-        {
-            CatTitle = item.CatTitle,
-            CatString = item.CatString,
-            UpdateProcedure = 0
-        };
-        editingId = item.Guid;
-        isEditing = true;
-        showForm = true;
-        infoMessage = null;
-        errorMessage = null;
-    }
-
-    private async Task HandleSubmit()
-    {
-        errorMessage = null;
-        infoMessage = null;
-
-        try
-        {
-            if (isEditing)
-            {
-                var updated = await Api.UpdateAsync(editingId, formModel);
-                if (!updated.Success)
-                {
-                    errorMessage = updated.Error ?? "Aktualisierung fehlgeschlagen.";
-                    return;
-                }
-
-                infoMessage = "Katalog aktualisiert.";
-            }
-            else
-            {
-                var created = await Api.CreateAsync(formModel);
-                if (!created.Success || created.Value == null)
-                {
-                    errorMessage = created.Error ?? "Anlegen fehlgeschlagen.";
-                    return;
-                }
-
-                infoMessage = "Katalog angelegt.";
-            }
-
-            showForm = false;
-            await LoadCatalogs();
-        }
-        catch (Exception ex)
-        {
-            errorMessage = $"Fehler beim Speichern: {ex.Message}";
-        }
-    }
-
-    private void CancelEdit()
-    {
-        showForm = false;
-        infoMessage = null;
-        errorMessage = null;
-    }
-
-    private async Task DeleteCatalog(int id)
-    {
-        errorMessage = null;
-        infoMessage = null;
-
-        try
-        {
-            var deleted = await Api.DeleteAsync(id);
-            if (!deleted.Success)
-            {
-                errorMessage = deleted.Error ?? "Löschen fehlgeschlagen.";
-                return;
-            }
-
-            infoMessage = "Katalog gelöscht.";
-            await LoadCatalogs();
-        }
-        catch (Exception ex)
-        {
-            errorMessage = $"Fehler beim Löschen: {ex.Message}";
-        }
-    }
-}

DbFirst.BlazorWasm/Pages/Home.razor

@@ -1,7 +0,0 @@
-@page "/"
-
-<PageTitle>Home</PageTitle>
-
-<h1>Hello, world!</h1>
-
-Welcome to your new app.

DbFirst.BlazorWasm/Program.cs

@@ -1,14 +0,0 @@
-using Microsoft.AspNetCore.Components.Web;
-using Microsoft.AspNetCore.Components.WebAssembly.Hosting;
-using DbFirst.BlazorWasm;
-using DbFirst.BlazorWasm.Services;
-
-var builder = WebAssemblyHostBuilder.CreateDefault(args);
-builder.RootComponents.Add<App>("#app");
-builder.RootComponents.Add<HeadOutlet>("head::after");
-
-var apiBaseUrl = builder.Configuration["ApiBaseUrl"] ?? builder.HostEnvironment.BaseAddress;
-builder.Services.AddScoped(sp => new HttpClient { BaseAddress = new Uri(apiBaseUrl) });
-builder.Services.AddScoped<CatalogApiClient>();
-
-await builder.Build().RunAsync();

DbFirst.BlazorWasm/Properties/launchSettings.json

@@ -1,41 +0,0 @@
-{
-  "$schema": "http://json.schemastore.org/launchsettings.json",
-  "iisSettings": {
-    "windowsAuthentication": false,
-    "anonymousAuthentication": true,
-    "iisExpress": {
-      "applicationUrl": "http://localhost:12804",
-      "sslPort": 44394
-    }
-  },
-  "profiles": {
-    "http": {
-      "commandName": "Project",
-      "dotnetRunMessages": true,
-      "launchBrowser": true,
-      "inspectUri": "{wsProtocol}://{url.hostname}:{url.port}/_framework/debug/ws-proxy?browser={browserInspectUri}",
-      "applicationUrl": "http://localhost:5101",
-      "environmentVariables": {
-        "ASPNETCORE_ENVIRONMENT": "Development"
-      }
-    },
-    "https": {
-      "commandName": "Project",
-      "dotnetRunMessages": true,
-      "launchBrowser": true,
-      "inspectUri": "{wsProtocol}://{url.hostname}:{url.port}/_framework/debug/ws-proxy?browser={browserInspectUri}",
-      "applicationUrl": "https://localhost:7276;http://localhost:5101",
-      "environmentVariables": {
-        "ASPNETCORE_ENVIRONMENT": "Development"
-      }
-    },
-    "IIS Express": {
-      "commandName": "IISExpress",
-      "launchBrowser": true,
-      "inspectUri": "{wsProtocol}://{url.hostname}:{url.port}/_framework/debug/ws-proxy?browser={browserInspectUri}",
-      "environmentVariables": {
-        "ASPNETCORE_ENVIRONMENT": "Development"
-      }
-    }
-  }
-}

DbFirst.BlazorWasm/_Imports.razor

@@ -1,12 +0,0 @@
-@using System.Net.Http
-@using System.Net.Http.Json
-@using Microsoft.AspNetCore.Components.Forms
-@using Microsoft.AspNetCore.Components.Routing
-@using Microsoft.AspNetCore.Components.Web
-@using Microsoft.AspNetCore.Components.Web.Virtualization
-@using Microsoft.AspNetCore.Components.WebAssembly.Http
-@using Microsoft.JSInterop
-@using DbFirst.BlazorWasm
-@using DbFirst.BlazorWasm.Layout
-@using DbFirst.BlazorWasm.Models
-@using DbFirst.BlazorWasm.Services

DbFirst.BlazorWasm/wwwroot/appsettings.json

@@ -1,3 +0,0 @@
-{
-  "ApiBaseUrl": "https://localhost:7204/"
-}

DbFirst.BlazorWasm/wwwroot/css/app.css

@@ -1,103 +0,0 @@
-html, body {
-    font-family: 'Helvetica Neue', Helvetica, Arial, sans-serif;
-}
-
-h1:focus {
-    outline: none;
-}
-
-a, .btn-link {
-    color: #0071c1;
-}
-
-.btn-primary {
-    color: #fff;
-    background-color: #1b6ec2;
-    border-color: #1861ac;
-}
-
-.btn:focus, .btn:active:focus, .btn-link.nav-link:focus, .form-control:focus, .form-check-input:focus {
-  box-shadow: 0 0 0 0.1rem white, 0 0 0 0.25rem #258cfb;
-}
-
-.content {
-    padding-top: 1.1rem;
-}
-
-.valid.modified:not([type=checkbox]) {
-    outline: 1px solid #26b050;
-}
-
-.invalid {
-    outline: 1px solid red;
-}
-
-.validation-message {
-    color: red;
-}
-
-#blazor-error-ui {
-    background: lightyellow;
-    bottom: 0;
-    box-shadow: 0 -1px 2px rgba(0, 0, 0, 0.2);
-    display: none;
-    left: 0;
-    padding: 0.6rem 1.25rem 0.7rem 1.25rem;
-    position: fixed;
-    width: 100%;
-    z-index: 1000;
-}
-
-    #blazor-error-ui .dismiss {
-        cursor: pointer;
-        position: absolute;
-        right: 0.75rem;
-        top: 0.5rem;
-    }
-
-.blazor-error-boundary {
-    background: url(data:image/svg+xml;base64,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) no-repeat 1rem/1.8rem, #b32121;
-    padding: 1rem 1rem 1rem 3.7rem;
-    color: white;
-}
-
-    .blazor-error-boundary::after {
-        content: "An error has occurred."
-    }
-
-.loading-progress {
-    position: relative;
-    display: block;
-    width: 8rem;
-    height: 8rem;
-    margin: 20vh auto 1rem auto;
-}
-
-    .loading-progress circle {
-        fill: none;
-        stroke: #e0e0e0;
-        stroke-width: 0.6rem;
-        transform-origin: 50% 50%;
-        transform: rotate(-90deg);
-    }
-
-        .loading-progress circle:last-child {
-            stroke: #1b6ec2;
-            stroke-dasharray: calc(3.141 * var(--blazor-load-percentage, 0%) * 0.8), 500%;
-            transition: stroke-dasharray 0.05s ease-in-out;
-        }
-
-.loading-progress-text {
-    position: absolute;
-    text-align: center;
-    font-weight: bold;
-    inset: calc(20vh + 3.25rem) 0 auto 0.2rem;
-}
-
-    .loading-progress-text:after {
-        content: var(--blazor-load-percentage-text, "Loading");
-    }
-
-code {
-    color: #c02d76;
-}

DbFirst.BlazorWasm/wwwroot/index.html

@@ -1,32 +0,0 @@
-<!DOCTYPE html>
-<html lang="en">
-
-<head>
-    <meta charset="utf-8" />
-    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
-    <title>DbFirst.BlazorWasm</title>
-    <base href="/" />
-    <link rel="stylesheet" href="css/bootstrap/bootstrap.min.css" />
-    <link rel="stylesheet" href="css/app.css" />
-    <link rel="icon" type="image/png" href="favicon.png" />
-    <link href="DbFirst.BlazorWasm.styles.css" rel="stylesheet" />
-</head>
-
-<body>
-    <div id="app">
-        <svg class="loading-progress">
-            <circle r="40%" cx="50%" cy="50%" />
-            <circle r="40%" cx="50%" cy="50%" />
-        </svg>
-        <div class="loading-progress-text"></div>
-    </div>
-
-    <div id="blazor-error-ui">
-        An unhandled error has occurred.
-        <a href="" class="reload">Reload</a>
-        <a class="dismiss">🗙</a>
-    </div>
-    <script src="_framework/blazor.webassembly.js"></script>
-</body>
-
-</html>

DbFirst.BlazorWebApp/Components/App.razor

@@ -0,0 +1,37 @@
+<!DOCTYPE html>
+<html lang="en">
+
+<head>
+    <meta charset="utf-8" />
+    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
+    <base href="/" />
+    @DxResourceManager.RegisterTheme(Themes.Fluent.Clone(properties =>
+    {
+        properties.ApplyToPageElements = true;
+    }))
+    @DxResourceManager.RegisterScripts()
+
+    <link href="_content/DevExpress.Blazor.Dashboard/ace.css" rel="stylesheet" />
+    <link href="_content/DevExpress.Blazor.Dashboard/ace-theme-dreamweaver.css" rel="stylesheet" />
+    <link href="_content/DevExpress.Blazor.Dashboard/ace-theme-ambiance.css" rel="stylesheet" />
+    <link href="_content/DevExpress.Blazor.Dashboard/dx.light.css" rel="stylesheet" />
+    <link href="_content/DevExpress.Blazor.Dashboard/dx-analytics.common.css" rel="stylesheet" />
+    <link href="_content/DevExpress.Blazor.Dashboard/dx-analytics.light.css" rel="stylesheet" />
+    <link href="_content/DevExpress.Blazor.Dashboard/dx-querybuilder.css" rel="stylesheet" />
+    <link href="_content/DevExpress.Blazor.Dashboard/dx-dashboard.light.min.css" rel="stylesheet" />
+
+    <link rel="stylesheet" href="bootstrap/bootstrap.min.css" />
+
+    <link rel="stylesheet" href="app.css" />
+    <link rel="stylesheet" href="DbFirst.BlazorWebApp.styles.css" />
+    <link rel="icon" type="image/png" href="favicon.png" />
+    <script src="js/size-manager.js"></script>
+    <HeadOutlet />
+</head>
+
+<body>
+    <Routes />
+    <script src="_framework/blazor.web.js"></script>
+</body>
+
+</html>

DbFirst.BlazorWebApp/Components/CatalogsGrid.razor

@@ -0,0 +1,578 @@
+@inject CatalogApiClient Api
+@inject BandLayoutService BandLayoutService
+
+@if (!string.IsNullOrWhiteSpace(errorMessage))
+{
+    <div class="alert alert-danger" role="alert">@errorMessage</div>
+}
+else if (!string.IsNullOrWhiteSpace(infoMessage))
+{
+    <div class="alert alert-success" role="alert">@infoMessage</div>
+}
+
+@if (!hasLoaded || isLoading)
+{
+    <div class="loading-container">
+        <div class="spinner-border text-primary" role="status">
+            <span class="visually-hidden">Lade...</span>
+        </div>
+    </div>
+}
+else if (items.Count == 0)
+{
+    <p>Keine Einträge vorhanden.</p>
+}
+else
+{
+    <div class="band-editor">
+        <button class="band-editor-toggle" @onclick="() => bandEditorExpanded = !bandEditorExpanded">
+            <span class="band-editor-toggle-icon @(bandEditorExpanded ? "expanded" : "")">&#9658;</span>
+            <span>Layout</span>
+        </button>
+        @if (bandEditorExpanded)
+        {
+            <div class="band-editor-body">
+                <div class="band-controls">
+                    <DxButton Text="Band hinzufügen" Click="AddBand" />
+                    <DxButton Text="Layout speichern" Click="SaveLayoutAsync" Enabled="@CanSaveBandLayout" />
+                    <DxButton Text="Layout zurücksetzen" Click="ResetLayoutAsync" />
+                </div>
+                @foreach (var band in bandLayout.Bands)
+                {
+                    <div class="band-row">
+                        <DxTextBox Text="@band.Caption" TextChanged="@(value => UpdateBandCaption(band, value))" />
+                        <DxButton Text="Entfernen" Click="@(() => RemoveBand(band))" />
+                    </div>
+                }
+                <DxFormLayout CssClass="band-columns" ColCount="2">
+                    @foreach (var column in columnDefinitions)
+                    {
+                        <DxFormLayoutItem Caption="@column.Caption">
+                            <DxComboBox Data="@bandOptions"
+                                        TData="BandOption"
+                                        TValue="string"
+                                        TextFieldName="Caption"
+                                        ValueFieldName="Id"
+                                        Value="@GetColumnBand(column.FieldName)"
+                                        ValueChanged="@(value => UpdateColumnBand(column.FieldName, value))"
+                                        Width="100%" />
+                        </DxFormLayoutItem>
+                    }
+                </DxFormLayout>
+            </div>
+        }
+    </div>
+
+    <div class="grid-section">
+        <DxGrid Data="@items"
+                TItem="CatalogReadDto"
+                KeyFieldName="@nameof(CatalogReadDto.Guid)"
+                SizeMode="@_sizeMode"
+                ShowGroupPanel="true"
+                ShowGroupedColumns="true"
+                AllowGroup="true"
+                FilterMenuButtonDisplayMode="GridFilterMenuButtonDisplayMode.Always"
+                AllowColumnResize="true"
+                ColumnResizeMode="GridColumnResizeMode.ColumnsContainer"
+                AllowColumnReorder="true"
+                PageSize="10"
+                CssClass="mb-4 catalog-grid"
+                EditMode="GridEditMode.PopupEditForm"
+                PopupEditFormCssClass="catalog-edit-popup"
+                PopupEditFormHeaderText="@popupHeaderText"
+                CustomizeEditModel="OnCustomizeEditModel"
+                EditModelSaving="OnEditModelSaving"
+                DataItemDeleting="OnDataItemDeleting"
+                FocusedRowEnabled="true"
+                @bind-FocusedRowKey="focusedRowKey"
+                @ref="gridRef">
+            <ToolbarTemplate>
+                <DxToolbar>
+                    <DxToolbarItem Alignment="ToolbarItemAlignment.Right">
+                        <Template Context="_">
+                            <DxDropDownButton Text="@FormatSizeText(_sizeMode)"
+                                              RenderStyle="ButtonRenderStyle.Secondary"
+                                              RenderStyleMode="ButtonRenderStyleMode.Text"
+                                              ItemClick="OnSizeChange">
+                                <Items>
+                                    @foreach (var size in _sizeModes)
+                                    {
+                                        <DxDropDownButtonItem Text="@FormatSizeText(size)" Id="@size.ToString()" />
+                                    }
+                                </Items>
+                            </DxDropDownButton>
+                        </Template>
+                    </DxToolbarItem>
+                </DxToolbar>
+            </ToolbarTemplate>
+            <Columns>
+                @RenderColumns()
+            </Columns>
+            <EditFormTemplate Context="editFormContext">
+                @{
+                    SetEditContext(editFormContext.EditContext); var editModel = (CatalogEditModel)editFormContext.EditModel; SetPopupHeaderText(editModel.IsNew);
+                }
+                <DxFormLayout ColCount="2">
+                    <DxFormLayoutItem Caption="Titel">
+                        <DxTextBox @bind-Text="editModel.CatTitle" Width="100%" />
+                    </DxFormLayoutItem>
+                    <DxFormLayoutItem Caption="Kennung">
+                        <DxTextBox @bind-Text="editModel.CatString" Width="100%" />
+                    </DxFormLayoutItem>
+                    @if (!editModel.IsNew)
+                    {
+                        <DxFormLayoutItem Caption="Update-Prozedur">
+                            <DxComboBox Data="@procedureOptions"
+                                        TData="ProcedureOption"
+                                        TValue="int"
+                                        TextFieldName="Text"
+                                        ValueFieldName="Value"
+                                        @bind-Value="editModel.UpdateProcedure"
+                                        Width="100%" />
+                        </DxFormLayoutItem>
+                    }
+                    <DxFormLayoutItem ColSpanMd="12">
+                        <ValidationSummary />
+                    </DxFormLayoutItem>
+                </DxFormLayout>
+            </EditFormTemplate>
+        </DxGrid>
+    </div>
+}
+
+@code {
+    private List<CatalogReadDto> items = new();
+    private bool isLoading;
+    private bool hasLoaded;
+    private string? errorMessage;
+    private string? infoMessage;
+    private EditContext? editContext;
+    private ValidationMessageStore? validationMessageStore;
+    private IGrid? gridRef;
+    private int? focusedRowKey;
+    private string popupHeaderText = "Edit";
+    private const string LayoutType = "GRID_BANDS";
+    private const string LayoutKey = "CatalogsGrid";
+    private string? layoutUser;
+    private BandLayout bandLayout = new();
+    private Dictionary<string, string> columnBandAssignments = new();
+    private List<BandOption> bandOptions = new();
+    private Dictionary<string, ColumnDefinition> columnLookup = new();
+    private bool gridLayoutApplied;
+    private bool bandEditorExpanded;
+
+    private List<ColumnDefinition> columnDefinitions = new()
+    {
+        new() { FieldName = nameof(CatalogReadDto.Guid), Caption = "Id", Width = "140px", FilterType = ColumnFilterType.Text },
+        new() { FieldName = nameof(CatalogReadDto.CatTitle), Caption = "Titel", FilterType = ColumnFilterType.Text },
+        new() { FieldName = nameof(CatalogReadDto.CatString), Caption = "String", FilterType = ColumnFilterType.Text },
+        new() { FieldName = nameof(CatalogReadDto.AddedWho), Caption = "Angelegt von", ReadOnly = true, FilterType = ColumnFilterType.Text },
+        new() { FieldName = nameof(CatalogReadDto.AddedWhen), Caption = "Angelegt am", ReadOnly = true, FilterType = ColumnFilterType.Date },
+        new() { FieldName = nameof(CatalogReadDto.ChangedWho), Caption = "Geändert von", ReadOnly = true, FilterType = ColumnFilterType.Text },
+        new() { FieldName = nameof(CatalogReadDto.ChangedWhen), Caption = "Geändert am", ReadOnly = true, FilterType = ColumnFilterType.Date }
+    };
+
+    private readonly List<ProcedureOption> procedureOptions = new()
+    {
+        new() { Value = 0, Text = "PRTBMY_CATALOG_UPDATE" },
+        new() { Value = 1, Text = "PRTBMY_CATALOG_SAVE" }
+    };
+
+    private bool CanSaveBandLayout => !string.IsNullOrWhiteSpace(layoutUser);
+
+    private SizeMode _sizeMode = SizeMode.Medium;
+    private static readonly List<SizeMode> _sizeModes = Enum.GetValues<SizeMode>().ToList();
+
+    private string FormatSizeText(SizeMode size) => size switch
+    {
+        SizeMode.Small => "Klein",
+        SizeMode.Medium => "Mittel",
+        SizeMode.Large => "Groß",
+        _ => size.ToString()
+    };
+
+    private void OnSizeChange(DropDownButtonItemClickEventArgs args)
+    {
+        _sizeMode = Enum.Parse<SizeMode>(args.ItemInfo.Id);
+    }
+
+    protected override async Task OnInitializedAsync()
+    {
+        columnLookup = columnDefinitions.ToDictionary(c => c.FieldName, StringComparer.OrdinalIgnoreCase);
+        layoutUser = await BandLayoutService.EnsureLayoutUserAsync();
+        bandLayout = await BandLayoutService.LoadBandLayoutAsync(LayoutType, LayoutKey, layoutUser, columnLookup);
+        columnBandAssignments = BandLayoutService.BuildAssignmentsFromLayout(bandLayout);
+        ApplyColumnLayoutFromStorage();
+        _sizeMode = bandLayout.SizeMode;
+        UpdateBandOptions();
+        await LoadCatalogs();
+    }
+
+    protected override async Task OnAfterRenderAsync(bool firstRender)
+    {
+        if (!gridLayoutApplied && gridRef != null && bandLayout.GridLayout != null)
+        {
+            gridRef.LoadLayout(bandLayout.GridLayout);
+            gridLayoutApplied = true;
+            await InvokeAsync(StateHasChanged);
+        }
+    }
+
+    private async Task LoadCatalogs()
+    {
+        isLoading = true;
+        errorMessage = null;
+        try
+        {
+            items = await Api.GetAllAsync();
+        }
+        catch (Exception ex)
+        {
+            errorMessage = $"Kataloge konnten nicht geladen werden: {ex.Message}";
+        }
+        finally
+        {
+            isLoading = false;
+            hasLoaded = true;
+            StateHasChanged();
+        }
+    }
+
+    private async Task SaveLayoutAsync()
+    {
+        if (string.IsNullOrWhiteSpace(layoutUser))
+            return;
+
+        try
+        {
+            CaptureColumnLayoutFromGrid();
+            await BandLayoutService.SaveBandLayoutAsync(LayoutType, LayoutKey, layoutUser, bandLayout);
+            infoMessage = "Layout gespeichert.";
+            errorMessage = null;
+        }
+        catch (Exception ex)
+        {
+            errorMessage = $"Layout konnte nicht gespeichert werden: {ex.Message}";
+        }
+    }
+
+    private async Task ResetLayoutAsync()
+    {
+        if (string.IsNullOrWhiteSpace(layoutUser))
+            return;
+
+        await BandLayoutService.ResetBandLayoutAsync(LayoutType, LayoutKey, layoutUser);
+
+        bandLayout = new BandLayout();
+        columnBandAssignments.Clear();
+        UpdateBandOptions();
+
+        foreach (var column in columnDefinitions)
+            column.Width = null;
+        columnLookup = columnDefinitions.ToDictionary(c => c.FieldName, StringComparer.OrdinalIgnoreCase);
+
+        _sizeMode = SizeMode.Medium;
+
+        if (gridRef != null)
+            gridRef.LoadLayout(new GridPersistentLayout());
+        gridLayoutApplied = false;
+
+        infoMessage = "Layout zurückgesetzt.";
+        errorMessage = null;
+    }
+
+    private void CaptureColumnLayoutFromGrid()
+    {
+        if (gridRef == null)
+            return;
+
+        var layout = gridRef.SaveLayout();
+        bandLayout.GridLayout = layout;
+        bandLayout.SizeMode = _sizeMode;
+
+        var orderedColumns = layout.Columns
+            .Where(c => !string.IsNullOrWhiteSpace(c.FieldName))
+            .OrderBy(c => c.VisibleIndex)
+            .ToList();
+
+        bandLayout.ColumnOrder = orderedColumns.Select(c => c.FieldName).ToList();
+        bandLayout.ColumnWidths = orderedColumns
+            .Where(c => !string.IsNullOrWhiteSpace(c.Width))
+            .ToDictionary(c => c.FieldName, c => c.Width, StringComparer.OrdinalIgnoreCase);
+    }
+
+    private void ApplyColumnLayoutFromStorage()
+    {
+        foreach (var column in columnDefinitions)
+        {
+            if (bandLayout.ColumnWidths.TryGetValue(column.FieldName, out var width) && !string.IsNullOrWhiteSpace(width))
+                column.Width = width;
+        }
+        columnLookup = columnDefinitions.ToDictionary(c => c.FieldName, StringComparer.OrdinalIgnoreCase);
+    }
+
+    private void AddBand()
+    {
+        bandLayout.Bands.Add(new BandDefinition { Id = Guid.NewGuid().ToString("N"), Caption = "Band" });
+        UpdateBandOptions();
+    }
+
+    private void RemoveBand(BandDefinition band)
+    {
+        bandLayout.Bands.Remove(band);
+        foreach (var key in columnBandAssignments.Where(p => p.Value == band.Id).Select(p => p.Key).ToList())
+            columnBandAssignments.Remove(key);
+        UpdateBandOptions();
+        SyncBandsFromAssignments();
+    }
+
+    private void UpdateBandCaption(BandDefinition band, string value)
+    {
+        band.Caption = value;
+        UpdateBandOptions();
+    }
+
+    private void UpdateColumnBand(string fieldName, string? bandId)
+    {
+        if (string.IsNullOrWhiteSpace(bandId))
+            columnBandAssignments.Remove(fieldName);
+        else
+            columnBandAssignments[fieldName] = bandId;
+        SyncBandsFromAssignments();
+    }
+
+    private string GetColumnBand(string fieldName)
+        => columnBandAssignments.TryGetValue(fieldName, out var bandId) ? bandId : string.Empty;
+
+    private void SyncBandsFromAssignments()
+    {
+        foreach (var band in bandLayout.Bands)
+        {
+            band.Columns = columnDefinitions
+                .Where(c => columnBandAssignments.TryGetValue(c.FieldName, out var id) && id == band.Id)
+                .Select(c => c.FieldName)
+                .ToList();
+        }
+        StateHasChanged();
+    }
+
+    private void UpdateBandOptions()
+    {
+        bandOptions = new List<BandOption> { new() { Id = string.Empty, Caption = "Ohne Band" } };
+        bandOptions.AddRange(bandLayout.Bands.Select(b => new BandOption { Id = b.Id, Caption = b.Caption }));
+    }
+
+    private RenderFragment RenderColumns() => builder =>
+    {
+        var seq = 0;
+        builder.OpenComponent<DxGridCommandColumn>(seq++);
+        builder.AddAttribute(seq++, "Width", "120px");
+        builder.CloseComponent();
+
+        var grouped = bandLayout.Bands.SelectMany(b => b.Columns).ToHashSet(StringComparer.OrdinalIgnoreCase);
+        foreach (var column in columnDefinitions.Where(c => !grouped.Contains(c.FieldName)))
+            BuildDataColumn(builder, ref seq, column);
+
+        foreach (var band in bandLayout.Bands)
+        {
+            if (band.Columns.Count == 0) continue;
+
+            builder.OpenComponent<DxGridBandColumn>(seq++);
+            builder.AddAttribute(seq++, "Caption", band.Caption);
+            builder.AddAttribute(seq++, "Columns", (RenderFragment)(bandBuilder =>
+            {
+                var bandSeq = 0;
+                foreach (var columnName in band.Columns)
+                {
+                    if (columnLookup.TryGetValue(columnName, out var column))
+                        BuildDataColumn(bandBuilder, ref bandSeq, column);
+                }
+            }));
+            builder.CloseComponent();
+        }
+    };
+
+    private void BuildDataColumn(RenderTreeBuilder builder, ref int seq, ColumnDefinition column)
+    {
+        builder.OpenComponent<DxGridDataColumn>(seq++);
+        builder.AddAttribute(seq++, "FieldName", column.FieldName);
+        builder.AddAttribute(seq++, "Caption", column.Caption);
+        if (!string.IsNullOrWhiteSpace(column.Width))
+            builder.AddAttribute(seq++, "Width", column.Width);
+        if (!string.IsNullOrWhiteSpace(column.DisplayFormat))
+            builder.AddAttribute(seq++, "DisplayFormat", column.DisplayFormat);
+        if (column.ReadOnly)
+            builder.AddAttribute(seq++, "ReadOnly", true);
+        builder.CloseComponent();
+    }
+
+    private void SetEditContext(EditContext context)
+    {
+        if (editContext == context) return;
+        if (editContext != null)
+            editContext.OnFieldChanged -= OnEditFieldChanged;
+        editContext = context;
+        validationMessageStore = new ValidationMessageStore(editContext);
+        editContext.OnFieldChanged += OnEditFieldChanged;
+    }
+
+    private void OnEditFieldChanged(object? sender, FieldChangedEventArgs e)
+    {
+        if (validationMessageStore == null || editContext == null) return;
+
+        if (e.FieldIdentifier.FieldName == nameof(CatalogEditModel.UpdateProcedure))
+        {
+            validationMessageStore.Clear();
+            editContext.NotifyValidationStateChanged();
+            return;
+        }
+
+        if (e.FieldIdentifier.FieldName == nameof(CatalogEditModel.CatTitle))
+        {
+            validationMessageStore.Clear(new FieldIdentifier(editContext.Model, nameof(CatalogEditModel.CatTitle)));
+            editContext.NotifyValidationStateChanged();
+        }
+    }
+
+    private void SetPopupHeaderText(bool isNew) => popupHeaderText = isNew ? "Neu" : "Edit";
+
+    private void OnCustomizeEditModel(GridCustomizeEditModelEventArgs e)
+    {
+        popupHeaderText = e.IsNew ? "Neu" : "Edit";
+        if (e.IsNew)
+        {
+            e.EditModel = new CatalogEditModel { IsNew = true };
+            return;
+        }
+
+        var item = (CatalogReadDto)e.DataItem;
+        e.EditModel = new CatalogEditModel
+        {
+            Guid = item.Guid,
+            CatTitle = item.CatTitle,
+            CatString = item.CatString,
+            UpdateProcedure = 0,
+            OriginalCatTitle = item.CatTitle,
+            IsNew = false
+        };
+    }
+
+    private async Task OnEditModelSaving(GridEditModelSavingEventArgs e)
+    {
+        errorMessage = null;
+        infoMessage = null;
+        validationMessageStore?.Clear();
+        editContext?.NotifyValidationStateChanged();
+
+        var editModel = (CatalogEditModel)e.EditModel;
+        if (!ValidateEditModel(editModel, e.IsNew))
+        {
+            e.Cancel = true;
+            return;
+        }
+
+        var dto = new CatalogWriteDto
+        {
+            CatTitle = editModel.CatTitle,
+            CatString = editModel.CatString,
+            UpdateProcedure = editModel.UpdateProcedure
+        };
+
+        try
+        {
+            if (e.IsNew)
+            {
+                var created = await Api.CreateAsync(dto);
+                if (!created.Success || created.Value == null)
+                {
+                    if (!string.IsNullOrWhiteSpace(created.Error))
+                        AddValidationError(editModel, nameof(CatalogEditModel.CatTitle), created.Error);
+                    else
+                        errorMessage = "Anlegen fehlgeschlagen.";
+                    e.Cancel = true;
+                    return;
+                }
+                infoMessage = "Katalog angelegt.";
+                focusedRowKey = created.Value.Guid;
+            }
+            else
+            {
+                var updated = await Api.UpdateAsync(editModel.Guid, dto);
+                if (!updated.Success)
+                {
+                    errorMessage = updated.Error ?? "Aktualisierung fehlgeschlagen.";
+                    e.Cancel = true;
+                    return;
+                }
+                infoMessage = "Katalog aktualisiert.";
+                focusedRowKey = editModel.Guid;
+            }
+
+            await LoadCatalogs();
+        }
+        catch (Exception ex)
+        {
+            errorMessage = $"Fehler beim Speichern: {ex.Message}";
+            e.Cancel = true;
+        }
+    }
+
+    private void AddValidationError(CatalogEditModel editModel, string fieldName, string message)
+    {
+        if (editContext == null || validationMessageStore == null) return;
+        validationMessageStore.Add(new FieldIdentifier(editModel, fieldName), message);
+        editContext.NotifyValidationStateChanged();
+    }
+
+    private bool ValidateEditModel(CatalogEditModel editModel, bool isNew)
+    {
+        if (isNew) return true;
+        if (editModel.UpdateProcedure == 0 &&
+            !string.Equals(editModel.CatTitle, editModel.OriginalCatTitle, StringComparison.OrdinalIgnoreCase))
+        {
+            AddValidationError(editModel, nameof(CatalogEditModel.CatTitle), "Titel kann nicht geändert werden.");
+            return false;
+        }
+        return true;
+    }
+
+    private async Task OnDataItemDeleting(GridDataItemDeletingEventArgs e)
+    {
+        errorMessage = null;
+        infoMessage = null;
+        var item = (CatalogReadDto)e.DataItem;
+        try
+        {
+            var deleted = await Api.DeleteAsync(item.Guid);
+            if (!deleted.Success)
+            {
+                errorMessage = deleted.Error ?? "Löschen fehlgeschlagen.";
+                e.Cancel = true;
+                return;
+            }
+            infoMessage = "Katalog gelöscht.";
+            await LoadCatalogs();
+        }
+        catch (Exception ex)
+        {
+            errorMessage = $"Fehler beim Löschen: {ex.Message}";
+            e.Cancel = true;
+        }
+    }
+
+    private sealed class CatalogEditModel
+    {
+        public int Guid { get; set; }
+        public string CatTitle { get; set; } = string.Empty;
+        public string CatString { get; set; } = string.Empty;
+        public int UpdateProcedure { get; set; }
+        public string OriginalCatTitle { get; set; } = string.Empty;
+        public bool IsNew { get; set; }
+    }
+
+    private sealed class ProcedureOption
+    {
+        public int Value { get; set; }
+        public string Text { get; set; } = string.Empty;
+    }
+}

DbFirst.BlazorWebApp/Components/CatalogsGrid.razor.css

@@ -0,0 +1,3 @@
+.catalog-edit-popup {
+    min-width: 720px;
+}

DbFirst.BlazorWebApp/Components/Layout/MainLayout.razor

@@ -0,0 +1,43 @@
+@inherits LayoutComponentBase
+@implements IDisposable
+@inject ThemeState ThemeState
+
+<div class="page @(ThemeState.IsDarkMode ? "app-dark" : "app-light")">
+    <div class="sidebar">
+        <NavMenu />
+    </div>
+
+    <main>
+        <div class="top-row px-4">
+            <DxButton Text="@(ThemeState.IsDarkMode ? "Dark Mode aus" : "Dark Mode an")" Click="ToggleTheme" />
+            <a href="https://learn.microsoft.com/aspnet/core/" target="_blank">About</a>
+        </div>
+
+        <article class="content px-4">
+            @Body
+        </article>
+    </main>
+</div>
+
+<div id="blazor-error-ui">
+    An unhandled error has occurred.
+    <a href="" class="reload">Reload</a>
+    <a class="dismiss">🗙</a>
+</div>
+
+@code {
+    protected override void OnInitialized()
+    {
+        ThemeState.OnChange += StateHasChanged;
+    }
+
+    private void ToggleTheme()
+    {
+        ThemeState.SetDarkMode(!ThemeState.IsDarkMode);
+    }
+
+    public void Dispose()
+    {
+        ThemeState.OnChange -= StateHasChanged;
+    }
+}

DbFirst.BlazorWebApp/Components/Layout/MainLayout.razor.css

@@ -4,14 +4,27 @@
     flex-direction: column;
 }
 
+.page.app-dark {
+    background-color: #1b1b1b;
+    color: #f1f1f1;
+}
+
 main {
     flex: 1;
 }
 
+.page.app-dark main {
+    background-color: #1b1b1b;
+}
+
 .sidebar {
     background-image: linear-gradient(180deg, rgb(5, 39, 103) 0%, #3a0647 70%);
 }
 
+.page.app-dark .sidebar {
+    background-image: linear-gradient(180deg, #171717 0%, #0f2a46 70%);
+}
+
 .top-row {
     background-color: #f7f7f7;
     border-bottom: 1px solid #d6d5d5;
@@ -21,6 +34,11 @@ main {
     align-items: center;
 }
 
+.page.app-dark .top-row {
+    background-color: #222;
+    border-bottom-color: #3d3d3d;
+}
+
     .top-row ::deep a, .top-row ::deep .btn-link {
         white-space: nowrap;
         margin-left: 1.5rem;
@@ -75,3 +93,22 @@ main {
         padding-right: 1.5rem !important;
     }
 }
+
+#blazor-error-ui {
+    background: lightyellow;
+    bottom: 0;
+    box-shadow: 0 -1px 2px rgba(0, 0, 0, 0.2);
+    display: none;
+    left: 0;
+    padding: 0.6rem 1.25rem 0.7rem 1.25rem;
+    position: fixed;
+    width: 100%;
+    z-index: 1000;
+}
+
+    #blazor-error-ui .dismiss {
+        cursor: pointer;
+        position: absolute;
+        right: 0.75rem;
+        top: 0.5rem;
+    }

DbFirst.BlazorWebApp/Components/Layout/NavMenu.razor

@@ -0,0 +1,42 @@
+<div class="top-row ps-3 navbar navbar-dark">
+    <div class="container-fluid">
+        <a class="navbar-brand" href="">DbFirst.BlazorWebApp</a>
+    </div>
+</div>
+
+<input type="checkbox" title="Navigation menu" class="navbar-toggler" />
+
+<div class="nav-scrollable" onclick="document.querySelector('.navbar-toggler').click()">
+    <nav class="flex-column">
+        <div class="nav-item px-3">
+            <NavLink class="nav-link" href="" Match="NavLinkMatch.All">
+                <span class="bi bi-house-door-fill-nav-menu" aria-hidden="true"></span> Home
+            </NavLink>
+        </div>
+
+        <div class="nav-item px-3">
+            <NavLink class="nav-link" href="catalogs">
+                <span class="bi bi-collection-nav-menu" aria-hidden="true"></span> Catalogs
+            </NavLink>
+        </div>
+
+        <div class="nav-item px-3">
+            <NavLink class="nav-link" href="dashboards">
+                <span class="bi bi-speedometer-nav-menu" aria-hidden="true"></span> Dashboards
+            </NavLink>
+        </div>
+
+        <div class="nav-item px-3">
+            <NavLink class="nav-link" href="massdata">
+                <span class="bi bi-table-nav-menu" aria-hidden="true"></span> MassData
+            </NavLink>
+        </div>
+
+        <div class="nav-item px-3">
+            <NavLink class="nav-link" href="clock">
+                <span class="bi bi-clock-nav-menu" aria-hidden="true"></span> Clock
+            </NavLink>
+        </div>
+    </nav>
+</div>
+

DbFirst.BlazorWebApp/Components/Layout/NavMenu.razor.css

@@ -1,5 +1,18 @@
 .navbar-toggler {
-    background-color: rgba(255, 255, 255, 0.1);
+    appearance: none;
+    cursor: pointer;
+    width: 3.5rem;
+    height: 2.5rem;
+    color: white;
+    position: absolute;
+    top: 0.5rem;
+    right: 1rem;
+    border: 1px solid rgba(255, 255, 255, 0.1);
+    background: url("data:image/svg+xml,%3csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 30 30'%3e%3cpath stroke='rgba%28255, 255, 255, 0.55%29' stroke-linecap='round' stroke-miterlimit='10' stroke-width='2' d='M4 7h22M4 15h22M4 23h22'/%3e%3c/svg%3e") no-repeat center/1.75rem rgba(255, 255, 255, 0.1);
+}
+
+.navbar-toggler:checked {
+    background-color: rgba(255, 255, 255, 0.5);
 }
 
 .top-row {
@@ -33,6 +46,18 @@
     background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='16' height='16' fill='white' class='bi bi-list-nested' viewBox='0 0 16 16'%3E%3Cpath fill-rule='evenodd' d='M4.5 11.5A.5.5 0 0 1 5 11h10a.5.5 0 0 1 0 1H5a.5.5 0 0 1-.5-.5zm-2-4A.5.5 0 0 1 3 7h10a.5.5 0 0 1 0 1H3a.5.5 0 0 1-.5-.5zm-2-4A.5.5 0 0 1 1 3h10a.5.5 0 0 1 0 1H1a.5.5 0 0 1-.5-.5z'/%3E%3C/svg%3E");
 }
 
+.bi-collection-nav-menu {
+    background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='16' height='16' fill='white' viewBox='0 0 16 16'%3E%3Cpath d='M2 3a.5.5 0 0 1 .5-.5h11a.5.5 0 0 1 .5.5v1H2V3z'/%3E%3Cpath d='M2 5h12v8a2 2 0 0 1-2 2H4a2 2 0 0 1-2-2V5z'/%3E%3C/svg%3E");
+}
+
+.bi-speedometer-nav-menu {
+    background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='16' height='16' fill='white' viewBox='0 0 16 16'%3E%3Cpath d='M1 11a1 1 0 0 0 1 1h2a1 1 0 0 0 1-1V7a1 1 0 0 0-1-1H2a1 1 0 0 0-1 1v4zm5 0a1 1 0 0 0 1 1h2a1 1 0 0 0 1-1V3a1 1 0 0 0-1-1H7a1 1 0 0 0-1 1v8zm5 0a1 1 0 0 0 1 1h2a1 1 0 0 0 1-1V9a1 1 0 0 0-1-1h-2a1 1 0 0 0-1 1v2z'/%3E%3C/svg%3E");
+}
+
+.bi-table-nav-menu {
+    background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='16' height='16' fill='white' viewBox='0 0 16 16'%3E%3Cpath d='M1 2a1 1 0 0 1 1-1h12a1 1 0 0 1 1 1v12a1 1 0 0 1-1 1H2a1 1 0 0 1-1-1V2zm1 1v2h12V3H2zm12 3H2v2h12V6zm0 3H2v2h12V9zm0 3H2v1h12v-1z'/%3E%3C/svg%3E");
+}
+
 .nav-item {
     font-size: 0.9rem;
     padding-bottom: 0.5rem;
@@ -46,13 +71,16 @@
         padding-bottom: 1rem;
     }
 
-    .nav-item ::deep a {
+    .nav-item ::deep .nav-link {
         color: #d7d7d7;
+        background: none;
+        border: none;
         border-radius: 4px;
         height: 3rem;
         display: flex;
         align-items: center;
         line-height: 3rem;
+        width: 100%;
     }
 
 .nav-item ::deep a.active {
@@ -60,22 +88,28 @@
     color: white;
 }
 
-.nav-item ::deep a:hover {
+.nav-item ::deep .nav-link:hover {
     background-color: rgba(255,255,255,0.1);
     color: white;
 }
 
+.nav-scrollable {
+    display: none;
+}
+
+.navbar-toggler:checked ~ .nav-scrollable {
+    display: block;
+}
+
 @media (min-width: 641px) {
     .navbar-toggler {
         display: none;
     }
 
-    .collapse {
+    .nav-scrollable {
         /* Never collapse the sidebar for wide screens */
         display: block;
-    }
-    
-    .nav-scrollable {
+
         /* Allow sidebar to scroll for tall menus */
         height: calc(100vh - 3.5rem);
         overflow-y: auto;

DbFirst.BlazorWebApp/Components/MassDataGrid.razor

@@ -0,0 +1,578 @@
+@inject MassDataApiClient Api
+@inject BandLayoutService BandLayoutService
+
+@if (!string.IsNullOrWhiteSpace(errorMessage))
+{
+    <div class="alert alert-danger" role="alert">@errorMessage</div>
+}
+else if (!string.IsNullOrWhiteSpace(infoMessage))
+{
+    <div class="alert alert-success" role="alert">@infoMessage</div>
+}
+
+@if (!hasLoaded || isLoading)
+{
+    <div class="loading-container">
+        <div class="spinner-border text-primary" role="status">
+            <span class="visually-hidden">Lade...</span>
+        </div>
+    </div>
+}
+else if (items.Count == 0)
+{
+    <p>Keine Einträge vorhanden.</p>
+}
+else
+{
+    
+    <div class="band-editor">
+        <button class="band-editor-toggle" @onclick="() => bandEditorExpanded = !bandEditorExpanded">
+            <span class="band-editor-toggle-icon @(bandEditorExpanded ? "expanded" : "")">&#9658;</span>
+            <span>Layout</span>
+        </button>
+        @if (bandEditorExpanded)
+        {
+            <div class="band-editor-body">
+                <div class="band-controls">
+                    <DxButton Text="Band hinzufügen" Click="AddBand" />
+                    <DxButton Text="Layout speichern" Click="SaveLayoutAsync" Enabled="@CanSaveBandLayout" />
+                    <DxButton Text="Layout zurücksetzen" Click="ResetLayoutAsync" />
+                </div>
+                @foreach (var band in bandLayout.Bands)
+                {
+                    <div class="band-row">
+                        <DxTextBox Text="@band.Caption" TextChanged="@(value => UpdateBandCaption(band, value))" />
+                        <DxButton Text="Entfernen" Click="@(() => RemoveBand(band))" />
+                    </div>
+                }
+                <DxFormLayout CssClass="band-columns" ColCount="2">
+                    @foreach (var column in columnDefinitions)
+                    {
+                        <DxFormLayoutItem Caption="@column.Caption">
+                            <DxComboBox Data="@bandOptions"
+                                        TData="BandOption"
+                                        TValue="string"
+                                        TextFieldName="Caption"
+                                        ValueFieldName="Id"
+                                        Value="@GetColumnBand(column.FieldName)"
+                                        ValueChanged="@(value => UpdateColumnBand(column.FieldName, value))"
+                                        Width="100%" />
+                        </DxFormLayoutItem>
+                    }
+                </DxFormLayout>
+            </div>
+        }
+    </div>
+
+    <div class="mb-3 page-size-selector">
+        <span class="page-size-label">Datensätze je Seite:</span>
+        <DxComboBox Data="@pageSizeOptions"
+                    TData="PageSizeOption"
+                    TValue="int?"
+                    TextFieldName="Text"
+                    ValueFieldName="Value"
+                    Value="@pageSize"
+                    ValueChanged="OnPageSizeChanged"
+                    CssClass="page-size-combo" />
+    </div>
+
+    <div class="grid-section">
+        <DxGrid Data="@items"
+                TItem="MassDataReadDto"
+                KeyFieldName="@nameof(MassDataReadDto.Id)"
+                SizeMode="@_sizeMode"
+                ShowGroupPanel="true"
+                ShowGroupedColumns="true"
+                AllowGroup="true"
+                FilterMenuButtonDisplayMode="GridFilterMenuButtonDisplayMode.Always"
+                AllowColumnResize="true"
+                ColumnResizeMode="GridColumnResizeMode.ColumnsContainer"
+                AllowColumnReorder="true"
+                PagerVisible="false"
+                PageSize="@(pageSize ?? 100)"
+                CssClass="mb-3 massdata-grid"
+                EditMode="GridEditMode.PopupEditForm"
+                PopupEditFormHeaderText="@popupHeaderText"
+                CustomizeEditModel="OnCustomizeEditModel"
+                EditModelSaving="OnEditModelSaving"
+                DataItemDeleting="OnDataItemDeleting"
+                FocusedRowEnabled="true"
+                @bind-FocusedRowKey="focusedRowKey"
+                @ref="gridRef">
+            <ToolbarTemplate>
+                <DxToolbar>
+                    <DxToolbarItem Alignment="ToolbarItemAlignment.Right">
+                        <Template Context="_">
+                            <DxDropDownButton Text="@FormatSizeText(_sizeMode)"
+                                              RenderStyle="ButtonRenderStyle.Secondary"
+                                              RenderStyleMode="ButtonRenderStyleMode.Text"
+                                              ItemClick="OnSizeChange">
+                                <Items>
+                                    @foreach (var size in _sizeModes)
+                                    {
+                                        <DxDropDownButtonItem Text="@FormatSizeText(size)" Id="@size.ToString()" />
+                                    }
+                                </Items>
+                            </DxDropDownButton>
+                        </Template>
+                    </DxToolbarItem>
+                </DxToolbar>
+            </ToolbarTemplate>
+            <Columns>
+                @RenderColumns()
+            </Columns>
+            <EditFormTemplate Context="editFormContext">
+                @{
+                    SetEditContext(editFormContext.EditContext); var editModel = (MassDataEditModel)editFormContext.EditModel; SetPopupHeaderText(editModel.IsNew);
+                }
+                <DxFormLayout ColCount="2">
+                    <DxFormLayoutItem Caption="CustomerName">
+                        <DxTextBox @bind-Text="editModel.CustomerName" Width="100%" />
+                    </DxFormLayoutItem>
+                    <DxFormLayoutItem Caption="Amount">
+                        <DxTextBox @bind-Text="editModel.AmountText" Width="100%" />
+                    </DxFormLayoutItem>
+                    <DxFormLayoutItem Caption="Category">
+                        <DxTextBox @bind-Text="editModel.Category" Width="100%" ReadOnly="@(!editModel.IsNew)" />
+                    </DxFormLayoutItem>
+                    <DxFormLayoutItem Caption="Status">
+                        <DxCheckBox @bind-Checked="editModel.StatusFlag" ReadOnly="@(!editModel.IsNew)" />
+                    </DxFormLayoutItem>
+                    @if (!editModel.IsNew)
+                    {
+                        <DxFormLayoutItem Caption="Prozedur">
+                            <DxComboBox Data="@procedureOptions"
+                                        TData="ProcedureOption"
+                                        TValue="int"
+                                        TextFieldName="Text"
+                                        ValueFieldName="Value"
+                                        @bind-Value="editModel.UpdateProcedure"
+                                        Width="100%" />
+                        </DxFormLayoutItem>
+                    }
+                    <DxFormLayoutItem ColSpanMd="12">
+                        <ValidationSummary />
+                    </DxFormLayoutItem>
+                </DxFormLayout>
+            </EditFormTemplate>
+        </DxGrid>
+
+        @if (pageCount > 1)
+        {
+            <div class="pager-container">
+                <DxPager PageCount="@pageCount" ActivePageIndex="@pageIndex" ActivePageIndexChanged="OnPageChanged" />
+            </div>
+        }
+    </div>
+}
+
+@code {
+    private List<MassDataReadDto> items = new();
+    private bool isLoading;
+    private bool hasLoaded;
+    private string? errorMessage;
+    private string? infoMessage;
+    private int pageIndex;
+    private int pageCount = 1;
+    private int? pageSize = 100;
+    private string popupHeaderText = "Edit";
+    private EditContext? editContext;
+    private ValidationMessageStore? validationMessageStore;
+    private IGrid? gridRef;
+    private int? focusedRowKey;
+    private const string LayoutType = "GRID_BANDS";
+    private const string LayoutKey = "MassDataGrid";
+    private string? layoutUser;
+    private BandLayout bandLayout = new();
+    private Dictionary<string, string> columnBandAssignments = new();
+    private List<BandOption> bandOptions = new();
+    private Dictionary<string, ColumnDefinition> columnLookup = new();
+    private bool gridLayoutApplied;
+    private bool bandEditorExpanded;
+
+    private List<ColumnDefinition> columnDefinitions = new()
+    {
+        new() { FieldName = nameof(MassDataReadDto.Id), Caption = "Id", Width = "90px", ReadOnly = true, FilterType = ColumnFilterType.Text },
+        new() { FieldName = nameof(MassDataReadDto.CustomerName), Caption = "CustomerName", FilterType = ColumnFilterType.Text },
+        new() { FieldName = nameof(MassDataReadDto.Amount), Caption = "Amount", DisplayFormat = "c2", FilterType = ColumnFilterType.Text },
+        new() { FieldName = nameof(MassDataReadDto.Category), Caption = "Category", ReadOnly = true, FilterType = ColumnFilterType.Text },
+        new() { FieldName = nameof(MassDataReadDto.StatusFlag), Caption = "Status", ReadOnly = true, FilterType = ColumnFilterType.Bool },
+        new() { FieldName = nameof(MassDataReadDto.AddedWhen), Caption = "Added", ReadOnly = true, FilterType = ColumnFilterType.Date },
+        new() { FieldName = nameof(MassDataReadDto.ChangedWhen), Caption = "Changed", ReadOnly = true, FilterType = ColumnFilterType.Date }
+    };
+
+    private readonly List<PageSizeOption> pageSizeOptions = new()
+    {
+        new() { Value = 100,    Text = "100" },
+        new() { Value = 1000,   Text = "1.000" },
+        new() { Value = 10000,  Text = "10.000" },
+        new() { Value = 100000, Text = "100.000" },
+        new() { Value = null,   Text = "Alle" }
+    };
+
+    private readonly List<ProcedureOption> procedureOptions = new()
+    {
+        new() { Value = 0, Text = "PRMassdata_UpsertByCustomerName" }
+    };
+
+    private bool CanSaveBandLayout => !string.IsNullOrWhiteSpace(layoutUser);
+
+    private SizeMode _sizeMode = SizeMode.Medium;
+    private static readonly List<SizeMode> _sizeModes = Enum.GetValues<SizeMode>().ToList();
+
+    private string FormatSizeText(SizeMode size) => size switch
+    {
+        SizeMode.Small => "Klein",
+        SizeMode.Medium => "Mittel",
+        SizeMode.Large => "Groß",
+        _ => size.ToString()
+    };
+
+    private void OnSizeChange(DropDownButtonItemClickEventArgs args)
+    {
+        _sizeMode = Enum.Parse<SizeMode>(args.ItemInfo.Id);
+    }
+
+    protected override async Task OnInitializedAsync()
+    {
+        columnLookup = columnDefinitions.ToDictionary(c => c.FieldName, StringComparer.OrdinalIgnoreCase);
+        layoutUser = await BandLayoutService.EnsureLayoutUserAsync();
+        bandLayout = await BandLayoutService.LoadBandLayoutAsync(LayoutType, LayoutKey, layoutUser, columnLookup);
+        columnBandAssignments = BandLayoutService.BuildAssignmentsFromLayout(bandLayout);
+        ApplyColumnLayoutFromStorage();
+        _sizeMode = bandLayout.SizeMode;
+        UpdateBandOptions();
+        await LoadPage(0);
+    }
+
+    protected override async Task OnAfterRenderAsync(bool firstRender)
+    {
+        if (!gridLayoutApplied && gridRef != null && bandLayout.GridLayout != null)
+        {
+            gridRef.LoadLayout(bandLayout.GridLayout);
+            gridLayoutApplied = true;
+            await InvokeAsync(StateHasChanged);
+        }
+    }
+
+    private async Task LoadPage(int page)
+    {
+        isLoading = true;
+        errorMessage = null;
+        try
+        {
+            var total = await Api.GetCountAsync();
+            var effectivePageSize = pageSize ?? (total == 0 ? 1 : total);
+            pageCount = Math.Max(1, (int)Math.Ceiling(total / (double)effectivePageSize));
+            pageIndex = Math.Clamp(page, 0, pageCount - 1);
+            var skip = pageSize.HasValue ? pageIndex * pageSize.Value : 0;
+            items = await Api.GetAllAsync(skip, pageSize);
+        }
+        catch (Exception ex)
+        {
+            errorMessage = $"MassData konnten nicht geladen werden: {ex.Message}";
+        }
+        finally
+        {
+            isLoading = false;
+            hasLoaded = true;
+            StateHasChanged();
+        }
+    }
+
+    private async Task OnPageChanged(int index) => await LoadPage(index);
+
+    private async Task OnPageSizeChanged(int? size)
+    {
+        pageSize = size;
+        await LoadPage(0);
+    }
+
+    private async Task SaveLayoutAsync()
+    {
+        if (string.IsNullOrWhiteSpace(layoutUser))
+            return;
+        try
+        {
+            CaptureColumnLayoutFromGrid();
+            await BandLayoutService.SaveBandLayoutAsync(LayoutType, LayoutKey, layoutUser, bandLayout);
+            infoMessage = "Layout gespeichert.";
+            errorMessage = null;
+        }
+        catch (Exception ex)
+        {
+            errorMessage = $"Layout konnte nicht gespeichert werden: {ex.Message}";
+        }
+    }
+
+    private async Task ResetLayoutAsync()
+    {
+        if (string.IsNullOrWhiteSpace(layoutUser))
+            return;
+        await BandLayoutService.ResetBandLayoutAsync(LayoutType, LayoutKey, layoutUser);
+        bandLayout = new BandLayout();
+        columnBandAssignments.Clear();
+        UpdateBandOptions();
+        foreach (var column in columnDefinitions)
+            column.Width = null;
+        columnLookup = columnDefinitions.ToDictionary(c => c.FieldName, StringComparer.OrdinalIgnoreCase);
+        _sizeMode = SizeMode.Medium;
+        if (gridRef != null)
+            gridRef.LoadLayout(new GridPersistentLayout());
+        gridLayoutApplied = false;
+        infoMessage = "Layout zurückgesetzt.";
+        errorMessage = null;
+    }
+
+    private void CaptureColumnLayoutFromGrid()
+    {
+        if (gridRef == null) return;
+        var layout = gridRef.SaveLayout();
+        bandLayout.GridLayout = layout;
+        bandLayout.SizeMode = _sizeMode;
+        var orderedColumns = layout.Columns
+            .Where(c => !string.IsNullOrWhiteSpace(c.FieldName))
+            .OrderBy(c => c.VisibleIndex)
+            .ToList();
+        bandLayout.ColumnOrder = orderedColumns.Select(c => c.FieldName).ToList();
+        bandLayout.ColumnWidths = orderedColumns
+            .Where(c => !string.IsNullOrWhiteSpace(c.Width))
+            .ToDictionary(c => c.FieldName, c => c.Width, StringComparer.OrdinalIgnoreCase);
+    }
+
+    private void ApplyColumnLayoutFromStorage()
+    {
+        foreach (var column in columnDefinitions)
+        {
+            if (bandLayout.ColumnWidths.TryGetValue(column.FieldName, out var width) && !string.IsNullOrWhiteSpace(width))
+                column.Width = width;
+        }
+        columnLookup = columnDefinitions.ToDictionary(c => c.FieldName, StringComparer.OrdinalIgnoreCase);
+    }
+
+    private void AddBand()
+    {
+        bandLayout.Bands.Add(new BandDefinition { Id = Guid.NewGuid().ToString("N"), Caption = "Band" });
+        UpdateBandOptions();
+    }
+
+    private void RemoveBand(BandDefinition band)
+    {
+        bandLayout.Bands.Remove(band);
+        foreach (var key in columnBandAssignments.Where(p => p.Value == band.Id).Select(p => p.Key).ToList())
+            columnBandAssignments.Remove(key);
+        UpdateBandOptions();
+        SyncBandsFromAssignments();
+    }
+
+    private void UpdateBandCaption(BandDefinition band, string value)
+    {
+        band.Caption = value;
+        UpdateBandOptions();
+    }
+
+    private void UpdateColumnBand(string fieldName, string? bandId)
+    {
+        if (string.IsNullOrWhiteSpace(bandId))
+            columnBandAssignments.Remove(fieldName);
+        else
+            columnBandAssignments[fieldName] = bandId;
+        SyncBandsFromAssignments();
+    }
+
+    private string GetColumnBand(string fieldName)
+        => columnBandAssignments.TryGetValue(fieldName, out var bandId) ? bandId : string.Empty;
+
+    private void SyncBandsFromAssignments()
+    {
+        foreach (var band in bandLayout.Bands)
+        {
+            band.Columns = columnDefinitions
+                .Where(c => columnBandAssignments.TryGetValue(c.FieldName, out var id) && id == band.Id)
+                .Select(c => c.FieldName)
+                .ToList();
+        }
+        StateHasChanged();
+    }
+
+    private void UpdateBandOptions()
+    {
+        bandOptions = new List<BandOption> { new() { Id = string.Empty, Caption = "Ohne Band" } };
+        bandOptions.AddRange(bandLayout.Bands.Select(b => new BandOption { Id = b.Id, Caption = b.Caption }));
+    }
+
+    private RenderFragment RenderColumns() => builder =>
+    {
+        var seq = 0;
+        builder.OpenComponent<DxGridCommandColumn>(seq++);
+        builder.AddAttribute(seq++, "Width", "120px");
+        builder.CloseComponent();
+        var grouped = bandLayout.Bands.SelectMany(b => b.Columns).ToHashSet(StringComparer.OrdinalIgnoreCase);
+        foreach (var column in columnDefinitions.Where(c => !grouped.Contains(c.FieldName)))
+            BuildDataColumn(builder, ref seq, column);
+        foreach (var band in bandLayout.Bands)
+        {
+            if (band.Columns.Count == 0) continue;
+            builder.OpenComponent<DxGridBandColumn>(seq++);
+            builder.AddAttribute(seq++, "Caption", band.Caption);
+            builder.AddAttribute(seq++, "Columns", (RenderFragment)(bandBuilder =>
+            {
+                var bandSeq = 0;
+                foreach (var columnName in band.Columns)
+                {
+                    if (columnLookup.TryGetValue(columnName, out var column))
+                        BuildDataColumn(bandBuilder, ref bandSeq, column);
+                }
+            }));
+            builder.CloseComponent();
+        }
+    };
+
+    private void BuildDataColumn(RenderTreeBuilder builder, ref int seq, ColumnDefinition column)
+    {
+        builder.OpenComponent<DxGridDataColumn>(seq++);
+        builder.AddAttribute(seq++, "FieldName", column.FieldName);
+        builder.AddAttribute(seq++, "Caption", column.Caption);
+        if (!string.IsNullOrWhiteSpace(column.Width))
+            builder.AddAttribute(seq++, "Width", column.Width);
+        if (!string.IsNullOrWhiteSpace(column.DisplayFormat))
+            builder.AddAttribute(seq++, "DisplayFormat", column.DisplayFormat);
+        if (column.ReadOnly)
+            builder.AddAttribute(seq++, "ReadOnly", true);
+        builder.CloseComponent();
+    }
+
+    private void SetEditContext(EditContext context)
+    {
+        if (editContext == context) return;
+        if (editContext != null)
+            editContext.OnFieldChanged -= OnEditFieldChanged;
+        editContext = context;
+        validationMessageStore = new ValidationMessageStore(editContext);
+        editContext.OnFieldChanged += OnEditFieldChanged;
+    }
+
+    private void OnEditFieldChanged(object? sender, FieldChangedEventArgs e)
+    {
+        if (validationMessageStore == null || editContext == null) return;
+        if (e.FieldIdentifier.FieldName == nameof(MassDataEditModel.UpdateProcedure))
+        {
+            validationMessageStore.Clear();
+            editContext.NotifyValidationStateChanged();
+            return;
+        }
+        if (e.FieldIdentifier.FieldName == nameof(MassDataEditModel.CustomerName))
+        {
+            validationMessageStore.Clear(new FieldIdentifier(editContext.Model, nameof(MassDataEditModel.CustomerName)));
+            editContext.NotifyValidationStateChanged();
+        }
+    }
+
+    private void SetPopupHeaderText(bool isNew) => popupHeaderText = isNew ? "Neu" : "Edit";
+
+    private async Task OnCustomizeEditModel(GridCustomizeEditModelEventArgs e)
+    {
+        if (e.IsNew)
+        {
+            e.EditModel = new MassDataEditModel { IsNew = true, UpdateProcedure = procedureOptions[0].Value };
+            SetPopupHeaderText(true);
+            return;
+        }
+        var item = (MassDataReadDto)e.DataItem;
+        e.EditModel = new MassDataEditModel
+        {
+            Id = item.Id,
+            CustomerName = item.CustomerName,
+            AmountText = item.Amount.ToString("0.00"),
+            Category = item.Category,
+            StatusFlag = item.StatusFlag,
+            UpdateProcedure = procedureOptions[0].Value,
+            IsNew = false,
+            OriginalCustomerName = item.CustomerName
+        };
+        SetPopupHeaderText(false);
+    }
+
+    private async Task OnEditModelSaving(GridEditModelSavingEventArgs e)
+    {
+        errorMessage = null;
+        infoMessage = null;
+        validationMessageStore?.Clear();
+        editContext?.NotifyValidationStateChanged();
+        var editModel = (MassDataEditModel)e.EditModel;
+        if (!decimal.TryParse(editModel.AmountText, out var amount))
+        {
+            AddValidationError(editModel, nameof(MassDataEditModel.AmountText), "Amount ist ungültig.");
+            e.Cancel = true;
+            return;
+        }
+        if (editModel.IsNew)
+        {
+            var existing = await Api.GetByCustomerNameAsync(editModel.CustomerName);
+            if (existing != null)
+            {
+                AddValidationError(editModel, nameof(MassDataEditModel.CustomerName), "Kunde existiert bereits.");
+                e.Cancel = true;
+                return;
+            }
+        }
+        var dto = new MassDataWriteDto
+        {
+            CustomerName = editModel.CustomerName,
+            Amount = amount,
+            Category = editModel.Category,
+            StatusFlag = editModel.StatusFlag
+        };
+        try
+        {
+            var saved = await Api.UpsertAsync(dto);
+            infoMessage = editModel.IsNew ? "MassData angelegt." : "MassData aktualisiert.";
+            focusedRowKey = saved.Id;
+            await LoadPage(pageIndex);
+        }
+        catch (Exception ex)
+        {
+            errorMessage = $"Fehler beim Speichern: {ex.Message}";
+            e.Cancel = true;
+        }
+    }
+
+    private void AddValidationError(MassDataEditModel editModel, string fieldName, string message)
+    {
+        if (editContext == null || validationMessageStore == null) return;
+        validationMessageStore.Add(new FieldIdentifier(editModel, fieldName), message);
+        editContext.NotifyValidationStateChanged();
+    }
+
+    private Task OnDataItemDeleting(GridDataItemDeletingEventArgs e)
+    {
+        errorMessage = null;
+        infoMessage = "Löschen ist aktuell noch nicht verfügbar.";
+        e.Cancel = true;
+        return Task.CompletedTask;
+    }
+
+    private sealed class MassDataEditModel
+    {
+        public int Id { get; set; }
+        public string CustomerName { get; set; } = string.Empty;
+        public string AmountText { get; set; } = string.Empty;
+        public string Category { get; set; } = string.Empty;
+        public bool StatusFlag { get; set; }
+        public int UpdateProcedure { get; set; }
+        public bool IsNew { get; set; }
+        public string OriginalCustomerName { get; set; } = string.Empty;
+    }
+
+    private sealed class ProcedureOption
+    {
+        public int Value { get; set; }
+        public string Text { get; set; } = string.Empty;
+    }
+
+    private sealed class PageSizeOption
+    {
+        public int? Value { get; set; }
+        public string Text { get; set; } = string.Empty;
+    }
+}

DbFirst.BlazorWebApp/Components/MassDataGrid.razor.css

@@ -0,0 +1,3 @@
+.massdata-edit-popup {
+    min-width: 720px;
+}

DbFirst.BlazorWebApp/Components/Pages/Catalogs.razor

@@ -0,0 +1,7 @@
+@page "/catalogs"
+
+<PageTitle>Catalogs</PageTitle>
+
+<h1>Catalogs</h1>
+
+<CatalogsGrid />

DbFirst.BlazorWebApp/Components/Pages/Clock.razor

@@ -0,0 +1,100 @@
+@rendermode InteractiveServer
+@page "/clock"
+@inject TimeApiClient TimeApi
+@implements IAsyncDisposable
+
+<PageTitle>Clock</PageTitle>
+
+<h3>DB Server Clock</h3>
+
+<div class="clock-wrapper">
+    <div class="clock-display @(_error != null ? "clock-error" : "")">
+        @if (_dbTime.HasValue)
+        {
+            <span class="clock-time">@_dbTime.Value.ToString("HH:mm:ss")</span>
+            <span class="clock-date">@_dbTime.Value.ToString("dd.MM.yyyy")</span>
+        }
+        else if (_error != null)
+        {
+            <span class="clock-time">--:--:--</span>
+            <span class="clock-date text-danger">@_error</span>
+        }
+        else
+        {
+            <span class="clock-time">...</span>
+        }
+    </div>
+</div>
+
+<style>
+    .clock-wrapper {
+        display: flex;
+        justify-content: center;
+        align-items: center;
+        height: 40vh;
+    }
+
+    .clock-display {
+        display: flex;
+        flex-direction: column;
+        align-items: center;
+        background: var(--bs-body-bg, #1e1e2e);
+        border: 2px solid var(--bs-border-color, #444);
+        border-radius: 1rem;
+        padding: 2rem 4rem;
+        box-shadow: 0 4px 24px rgba(0,0,0,0.3);
+    }
+
+    .clock-time {
+        font-size: 5rem;
+        font-weight: 700;
+        font-variant-numeric: tabular-nums;
+        letter-spacing: 0.1em;
+        color: var(--bs-primary, #0d6efd);
+    }
+
+    .clock-date {
+        font-size: 1.4rem;
+        margin-top: 0.5rem;
+        opacity: 0.75;
+    }
+
+    .clock-error .clock-time {
+        color: var(--bs-danger, #dc3545);
+    }
+</style>
+
+@code {
+    private DateTime? _dbTime;
+    private string? _error;
+    private Timer? _timer;
+
+    protected override async Task OnInitializedAsync()
+    {
+        await TickAsync();
+        _timer = new Timer(async _ =>
+        {
+            await TickAsync();
+            await InvokeAsync(StateHasChanged);
+        }, null, TimeSpan.FromSeconds(1), TimeSpan.FromSeconds(1));
+    }
+
+    private async Task TickAsync()
+    {
+        try
+        {
+            _dbTime = await TimeApi.InsertAndGetLastAsync();
+            _error = null;
+        }
+        catch (Exception ex)
+        {
+            _error = ex.Message;
+        }
+    }
+
+    public async ValueTask DisposeAsync()
+    {
+        if (_timer != null)
+            await _timer.DisposeAsync();
+    }
+}

DbFirst.BlazorWebApp/Components/Pages/Dashboard.razor

@@ -0,0 +1,123 @@
+@page "/dashboard"
+@page "/dashboards/{DashboardId?}"
+@implements IAsyncDisposable
+@inject Microsoft.Extensions.Configuration.IConfiguration Configuration
+@inject NavigationManager Navigation
+@inject DashboardApiClient DashboardApi
+
+<PageTitle>Dashboards</PageTitle>
+
+<div class="dashboard-shell">
+    <aside class="dashboard-nav">
+        <div class="dashboard-nav-title">Dashboards</div>
+        @if (dashboards.Count == 0)
+        {
+            <div class="px-3 py-2 text-muted">Keine Dashboards vorhanden.</div>
+        }
+        else
+        {
+            @foreach (var dashboard in dashboards)
+            {
+                <NavLink class="dashboard-nav-link" href="@($"dashboards/{dashboard.Id}?mode={(IsDesigner ? "designer" : "viewer")}")">@dashboard.Name</NavLink>
+            }
+        }
+    </aside>
+    <section class="dashboard-content">
+        <div class="mb-3">
+            <DxButton RenderStyle="ButtonRenderStyle.Primary" Click="@ToggleMode">
+                @(IsDesigner ? "Zum Viewer wechseln" : "Zum Designer wechseln")
+            </DxButton>
+        </div>
+        <DxDashboard @key="DashboardKey" Endpoint="@DashboardEndpoint" InitialDashboardId="@SelectedDashboardId" WorkingMode="@CurrentMode" style="width: 100%; height: 800px;">
+        </DxDashboard>
+    </section>
+</div>
+
+@code {
+    [Parameter] public string? DashboardId { get; set; }
+    [SupplyParameterFromQuery] public string? Mode { get; set; }
+
+    private readonly List<DashboardInfoDto> dashboards = new();
+    private HubConnection? _hubConnection;
+
+    private bool IsDesigner => !string.Equals(Mode, "viewer", StringComparison.OrdinalIgnoreCase);
+    private WorkingMode CurrentMode => IsDesigner ? WorkingMode.Designer : WorkingMode.ViewerOnly;
+    private string SelectedDashboardId { get; set; } = string.Empty;
+    private string DashboardKey => $"{SelectedDashboardId}-{(IsDesigner ? "designer" : "viewer")}";
+
+    private string DashboardEndpoint => $"{Configuration["ApiBaseUrl"]?.TrimEnd('/')}/api/dashboard";
+    private string HubEndpoint => $"{Configuration["ApiBaseUrl"]?.TrimEnd('/')}/hubs/dashboards";
+
+    protected override async Task OnInitializedAsync()
+    {
+        await RefreshDashboards();
+
+        _hubConnection = new HubConnectionBuilder()
+            .WithUrl(HubEndpoint)
+            .WithAutomaticReconnect()
+            .Build();
+
+        _hubConnection.On("DashboardsChanged", async () =>
+        {
+            await RefreshDashboards();
+        });
+
+        await _hubConnection.StartAsync();
+    }
+
+    protected override async Task OnParametersSetAsync()
+    {
+        if (dashboards.Count == 0)
+        {
+            await RefreshDashboards();
+        }
+
+        var requestedId = string.IsNullOrWhiteSpace(DashboardId) || string.Equals(DashboardId, "default", StringComparison.OrdinalIgnoreCase)
+            ? null
+            : DashboardId;
+
+        var resolved = !string.IsNullOrWhiteSpace(requestedId)
+            ? dashboards.FirstOrDefault(d => string.Equals(d.Id, requestedId, StringComparison.OrdinalIgnoreCase))
+            : dashboards.FirstOrDefault(d => string.Equals(d.Id, "DefaultDashboard", StringComparison.OrdinalIgnoreCase))
+              ?? dashboards.FirstOrDefault();
+
+        if (resolved == null)
+        {
+            return;
+        }
+
+        SelectedDashboardId = resolved.Id;
+
+        if (!string.Equals(DashboardId, resolved.Id, StringComparison.OrdinalIgnoreCase))
+        {
+            Navigation.NavigateTo($"dashboards/{resolved.Id}?mode={(IsDesigner ? "designer" : "viewer")}", replace: true);
+        }
+    }
+
+    private void ToggleMode()
+    {
+        var targetMode = IsDesigner ? "viewer" : "designer";
+        Navigation.NavigateTo($"dashboards/{SelectedDashboardId}?mode={targetMode}", replace: true);
+    }
+
+    private async Task RefreshDashboards()
+    {
+        var latest = await DashboardApi.GetAllAsync();
+        if (latest.Count == dashboards.Count && latest.All(d => dashboards.Any(x => x.Id == d.Id && x.Name == d.Name)))
+        {
+            return;
+        }
+
+        dashboards.Clear();
+        dashboards.AddRange(latest);
+        await InvokeAsync(StateHasChanged);
+    }
+
+    public async ValueTask DisposeAsync()
+    {
+        if (_hubConnection != null)
+        {
+            await _hubConnection.DisposeAsync();
+        }
+    }
+}

DbFirst.BlazorWebApp/Components/Pages/Dashboard.razor.css

@@ -0,0 +1,42 @@
+.dashboard-shell {
+    display: flex;
+    gap: 0;
+    min-height: 800px;
+    border: 1px solid #e6e6e6;
+    border-radius: 6px;
+    overflow: hidden;
+    background: #fff;
+}
+
+.dashboard-nav {
+    width: 220px;
+    border-right: 1px solid #e6e6e6;
+    background: #fafafa;
+}
+
+.dashboard-nav-title {
+    padding: 0.75rem 1rem 0.5rem;
+    font-size: 0.7rem;
+    text-transform: uppercase;
+    letter-spacing: 0.08em;
+    color: #6c757d;
+    font-weight: 600;
+}
+
+.dashboard-nav-link {
+    display: block;
+    padding: 0.55rem 1rem;
+    color: inherit;
+    text-decoration: none;
+}
+
+    .dashboard-nav-link.active {
+        background: #e9ecef;
+        font-weight: 600;
+    }
+
+.dashboard-content {
+    flex: 1;
+    min-width: 0;
+    padding: 1rem;
+}

DbFirst.BlazorWebApp/Components/Pages/Error.razor

@@ -0,0 +1,36 @@
+@page "/Error"
+@using System.Diagnostics
+
+<PageTitle>Error</PageTitle>
+
+<h1 class="text-danger">Error.</h1>
+<h2 class="text-danger">An error occurred while processing your request.</h2>
+
+@if (ShowRequestId)
+{
+    <p>
+        <strong>Request ID:</strong> <code>@RequestId</code>
+    </p>
+}
+
+<h3>Development Mode</h3>
+<p>
+    Swapping to <strong>Development</strong> environment will display more detailed information about the error that occurred.
+</p>
+<p>
+    <strong>The Development environment shouldn't be enabled for deployed applications.</strong>
+    It can result in displaying sensitive information from exceptions to end users.
+    For local debugging, enable the <strong>Development</strong> environment by setting the <strong>ASPNETCORE_ENVIRONMENT</strong> environment variable to <strong>Development</strong>
+    and restarting the app.
+</p>
+
+@code{
+    [CascadingParameter]
+    private HttpContext? HttpContext { get; set; }
+
+    private string? RequestId { get; set; }
+    private bool ShowRequestId => !string.IsNullOrEmpty(RequestId);
+
+    protected override void OnInitialized() =>
+        RequestId = Activity.Current?.Id ?? HttpContext?.TraceIdentifier;
+}

DbFirst.BlazorWebApp/Components/Pages/Home.razor

@@ -0,0 +1,43 @@
+@rendermode InteractiveServer
+
+@page "/"
+
+<PageTitle>Home</PageTitle>
+
+<h1>Database first</h1>
+
+<DxCarousel Width="100%"
+            Height="calc(100vh - 9rem)"
+            Data="@GetCarouselData()"
+            ImageSrcField="Source"
+            ImageAltField="AlternateText"
+            LoopNavigationEnabled="true"
+            SlideShowEnabled="true"
+            SlideShowDelay="3000"
+            PauseSlideShowOnHover="true"
+            ImageSizeMode="CarouselImageSizeMode.FitProportional">
+</DxCarousel>
+
+@code {
+    List<CarouselData> GetCarouselData()
+    {
+        return new List<CarouselData>
+        {
+            new CarouselData("/images/DbFirstBefehl.png", "DbFirstBefehl"),
+            new CarouselData("/images/CQRS - Katalog-Datenfluss.png", "CQRS - Katalog-Datenfluss"),
+            new CarouselData("/images/CQRS - Catalog Create, Update, Delete.png", "CQRS - Catalog Create, Update, Delete"),
+        };
+    }
+
+    public class CarouselData
+    {
+        public string Source { get; set; }
+        public string AlternateText { get; set; }
+
+        public CarouselData(string source, string alt)
+        {
+            Source = source;
+            AlternateText = alt;
+        }
+    }
+}

DbFirst.BlazorWebApp/Components/Pages/Massdata.razor

@@ -0,0 +1,7 @@
+@page "/massdata"
+
+<PageTitle>MassData</PageTitle>
+
+<h1>MassData</h1>
+
+<MassDataGrid />

DbFirst.BlazorWebApp/Components/Routes.razor

@@ -0,0 +1,8 @@
+@rendermode InteractiveServer
+
+<Router AppAssembly="typeof(Program).Assembly">
+    <Found Context="routeData">
+        <RouteView RouteData="routeData" DefaultLayout="typeof(Layout.MainLayout)" />
+        <FocusOnNavigate RouteData="routeData" Selector="h1" />
+    </Found>
+</Router>

DbFirst.BlazorWebApp/Components/_Imports.razor

@@ -0,0 +1,20 @@
+@using System.Net.Http
+@using System.Net.Http.Json
+@using System.Text.Json
+@using Microsoft.AspNetCore.Components.Forms
+@using Microsoft.AspNetCore.Components.Rendering
+@using Microsoft.AspNetCore.Components.Routing
+@using Microsoft.AspNetCore.Components.Web
+@using static Microsoft.AspNetCore.Components.Web.RenderMode
+@using Microsoft.AspNetCore.Components.Web.Virtualization
+@using Microsoft.JSInterop
+@using Microsoft.AspNetCore.SignalR.Client
+@using DbFirst.BlazorWebApp
+@using DbFirst.BlazorWebApp.Components
+@using DbFirst.BlazorWebApp.Models
+@using DbFirst.BlazorWebApp.Models.Grid
+@using DbFirst.BlazorWebApp.Services
+@using DevExpress.Blazor
+@using DevExpress.DashboardBlazor
+@using DevExpress.DashboardWeb
+@using DevExpress.Data.Filtering

DbFirst.BlazorWebApp/DbFirst.BlazorWebApp.csproj

@@ -0,0 +1,21 @@
+<Project Sdk="Microsoft.NET.Sdk.Web">
+
+  <PropertyGroup>
+    <TargetFramework>net8.0</TargetFramework>
+    <Nullable>enable</Nullable>
+    <ImplicitUsings>enable</ImplicitUsings>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <PackageReference Include="DevExpress.Blazor" Version="25.2.3" />
+    <PackageReference Include="DevExpress.Blazor.Dashboard" Version="25.2.3" />
+    <PackageReference Include="DevExpress.Blazor.Themes" Version="25.2.3" />
+    <PackageReference Include="DevExpress.Blazor.Themes.Fluent" Version="25.2.3" />
+    <PackageReference Include="Microsoft.AspNetCore.SignalR.Client" Version="8.0.22" />
+  </ItemGroup>
+
+  <ItemGroup>
+    <Folder Include="wwwroot\images\" />
+  </ItemGroup>
+
+</Project>

DbFirst.BlazorWebApp/Models/CatalogReadDto.cs

@@ -0,0 +1,12 @@
+namespace DbFirst.BlazorWebApp.Models;
+
+public class CatalogReadDto
+{
+    public int Guid { get; set; }
+    public string CatTitle { get; set; } = null!;
+    public string CatString { get; set; } = null!;
+    public string AddedWho { get; set; } = null!;
+    public DateTime AddedWhen { get; set; }
+    public string? ChangedWho { get; set; }
+    public DateTime? ChangedWhen { get; set; }
+}

DbFirst.BlazorWebApp/Models/CatalogWriteDto.cs

@@ -1,8 +1,8 @@
-namespace DbFirst.BlazorWasm.Models;
+namespace DbFirst.BlazorWebApp.Models;
 
 public class CatalogWriteDto
 {
     public string CatTitle { get; set; } = string.Empty;
     public string CatString { get; set; } = string.Empty;
-    public int UpdateProcedure { get; set; } = 0; // 0 = Update, 1 = Save
+    public int UpdateProcedure { get; set; }
 }

DbFirst.BlazorWebApp/Models/DashboardInfoDto.cs

@@ -0,0 +1,7 @@
+namespace DbFirst.BlazorWebApp.Models;
+
+public class DashboardInfoDto
+{
+    public string Id { get; set; } = string.Empty;
+    public string Name { get; set; } = string.Empty;
+}

DbFirst.BlazorWebApp/Models/Grid/BandLayoutModels.cs

@@ -0,0 +1,43 @@
+using DevExpress.Blazor;
+
+namespace DbFirst.BlazorWebApp.Models.Grid
+{
+    public class BandLayout
+    {
+        public List<BandDefinition> Bands { get; set; } = new();
+        public List<string> ColumnOrder { get; set; } = new();
+        public Dictionary<string, string?> ColumnWidths { get; set; } = new(StringComparer.OrdinalIgnoreCase);
+        public GridPersistentLayout? GridLayout { get; set; }
+        public SizeMode SizeMode { get; set; } = SizeMode.Medium;
+    }
+
+    public class BandDefinition
+    {
+        public string Id { get; set; } = string.Empty;
+        public string Caption { get; set; } = string.Empty;
+        public List<string> Columns { get; set; } = new();
+    }
+
+    public class BandOption
+    {
+        public string Id { get; set; } = string.Empty;
+        public string Caption { get; set; } = string.Empty;
+    }
+
+    public class ColumnDefinition
+    {
+        public string FieldName { get; init; } = string.Empty;
+        public string Caption { get; init; } = string.Empty;
+        public string? Width { get; set; }
+        public string? DisplayFormat { get; init; }
+        public bool ReadOnly { get; init; }
+        public ColumnFilterType FilterType { get; init; }
+    }
+
+    public enum ColumnFilterType
+    {
+        Text,
+        Bool,
+        Date
+    }
+}

DbFirst.BlazorWebApp/Models/LayoutDto.cs

@@ -0,0 +1,9 @@
+namespace DbFirst.BlazorWebApp.Models;
+
+public class LayoutDto
+{
+    public string LayoutType { get; set; } = string.Empty;
+    public string LayoutKey { get; set; } = string.Empty;
+    public string UserName { get; set; } = string.Empty;
+    public string LayoutData { get; set; } = string.Empty;
+}

DbFirst.BlazorWebApp/Models/MassDataReadDto.cs

@@ -0,0 +1,12 @@
+namespace DbFirst.BlazorWebApp.Models;
+
+public class MassDataReadDto
+{
+    public int Id { get; set; }
+    public string CustomerName { get; set; } = string.Empty;
+    public decimal Amount { get; set; }
+    public string Category { get; set; } = string.Empty;
+    public bool StatusFlag { get; set; }
+    public DateTime AddedWhen { get; set; }
+    public DateTime? ChangedWhen { get; set; }
+}

DbFirst.BlazorWebApp/Models/MassDataWriteDto.cs

@@ -0,0 +1,9 @@
+namespace DbFirst.BlazorWebApp.Models;
+
+public class MassDataWriteDto
+{
+    public string CustomerName { get; set; } = string.Empty;
+    public decimal Amount { get; set; }
+    public string Category { get; set; } = string.Empty;
+    public bool StatusFlag { get; set; }
+}

DbFirst.BlazorWebApp/Program.cs

@@ -0,0 +1,66 @@
+using DbFirst.BlazorWebApp.Components;
+using DbFirst.BlazorWebApp.Services;
+using DevExpress.Blazor;
+
+var builder = WebApplication.CreateBuilder(args);
+
+// Add services to the container.
+builder.Services.AddRazorComponents()
+    .AddInteractiveServerComponents();
+
+builder.Services.AddDevExpressBlazor(options => options.BootstrapVersion = BootstrapVersion.v5);
+builder.Services.AddScoped<ThemeState>();
+builder.Services.AddScoped<BandLayoutService>();
+
+var apiBaseUrl = builder.Configuration["ApiBaseUrl"];
+if (!string.IsNullOrWhiteSpace(apiBaseUrl))
+{
+    builder.Services.AddHttpClient<CatalogApiClient>(client =>
+    {
+        client.BaseAddress = new Uri(apiBaseUrl);
+    });
+    builder.Services.AddHttpClient<DashboardApiClient>(client =>
+    {
+        client.BaseAddress = new Uri(apiBaseUrl);
+    });
+    builder.Services.AddHttpClient<MassDataApiClient>(client =>
+    {
+        client.BaseAddress = new Uri(apiBaseUrl);
+    });
+    builder.Services.AddHttpClient<LayoutApiClient>(client =>
+    {
+        client.BaseAddress = new Uri(apiBaseUrl);
+    });
+    builder.Services.AddHttpClient<TimeApiClient>(client =>
+    {
+        client.BaseAddress = new Uri(apiBaseUrl);
+    });
+}
+else
+{
+    builder.Services.AddHttpClient<CatalogApiClient>();
+    builder.Services.AddHttpClient<DashboardApiClient>();
+    builder.Services.AddHttpClient<MassDataApiClient>();
+    builder.Services.AddHttpClient<LayoutApiClient>();
+    builder.Services.AddHttpClient<TimeApiClient>();
+}
+
+var app = builder.Build();
+
+// Configure the HTTP request pipeline.
+if (!app.Environment.IsDevelopment())
+{
+    app.UseExceptionHandler("/Error", createScopeForErrors: true);
+    // The default HSTS value is 30 days. You may want to change this for production scenarios, see https://aka.ms/aspnetcore-hsts.
+    app.UseHsts();
+}
+
+app.UseHttpsRedirection();
+
+app.UseStaticFiles();
+app.UseAntiforgery();
+
+app.MapRazorComponents<App>()
+    .AddInteractiveServerRenderMode();
+
+app.Run();

DbFirst.BlazorWebApp/Properties/launchSettings.json

@@ -0,0 +1,38 @@
+{
+  "$schema": "http://json.schemastore.org/launchsettings.json",
+    "iisSettings": {
+      "windowsAuthentication": false,
+      "anonymousAuthentication": true,
+      "iisExpress": {
+        "applicationUrl": "http://localhost:7440",
+        "sslPort": 44343
+      }
+    },
+    "profiles": {
+      "http": {
+        "commandName": "Project",
+        "dotnetRunMessages": true,
+        "launchBrowser": true,
+        "applicationUrl": "http://localhost:5096",
+        "environmentVariables": {
+          "ASPNETCORE_ENVIRONMENT": "Development"
+        }
+      },
+      "https": {
+        "commandName": "Project",
+        "dotnetRunMessages": true,
+        "launchBrowser": true,
+        "applicationUrl": "https://localhost:7191;http://localhost:5096",
+        "environmentVariables": {
+          "ASPNETCORE_ENVIRONMENT": "Development"
+        }
+      },
+      "IIS Express": {
+        "commandName": "IISExpress",
+        "launchBrowser": true,
+        "environmentVariables": {
+          "ASPNETCORE_ENVIRONMENT": "Development"
+        }
+      }
+    }
+  }

DbFirst.BlazorWebApp/Services/BandLayoutService.cs

@@ -0,0 +1,103 @@
+using DbFirst.BlazorWebApp.Models;
+using DbFirst.BlazorWebApp.Models.Grid;
+using Microsoft.JSInterop;
+using System.Text.Json;
+
+namespace DbFirst.BlazorWebApp.Services
+{
+    public class BandLayoutService(LayoutApiClient layoutApi, IJSRuntime jsRuntime)
+    {
+        private const string LayoutUserStorageKey = "layoutUser";
+        private readonly JsonSerializerOptions _jsonOptions = new(JsonSerializerDefaults.Web);
+
+        public async Task<string> EnsureLayoutUserAsync()
+        {
+            var layoutUser = await jsRuntime.InvokeAsync<string?>("localStorage.getItem", LayoutUserStorageKey);
+            if (string.IsNullOrWhiteSpace(layoutUser))
+            {
+                layoutUser = Guid.NewGuid().ToString("N");
+                await jsRuntime.InvokeVoidAsync("localStorage.setItem", LayoutUserStorageKey, layoutUser);
+            }
+            return layoutUser;
+        }
+
+        public async Task<BandLayout> LoadBandLayoutAsync(
+            string layoutType,
+            string layoutKey,
+            string layoutUser,
+            Dictionary<string, ColumnDefinition> columnLookup)
+        {
+            if (string.IsNullOrWhiteSpace(layoutUser))
+                return new BandLayout();
+
+            var stored = await layoutApi.GetAsync(layoutType, layoutKey, layoutUser);
+            if (stored != null && !string.IsNullOrWhiteSpace(stored.LayoutData))
+            {
+                var parsed = JsonSerializer.Deserialize<BandLayout>(stored.LayoutData, _jsonOptions);
+                return NormalizeBandLayout(parsed, columnLookup);
+            }
+
+            return new BandLayout();
+        }
+
+        public async Task SaveBandLayoutAsync(
+            string layoutType,
+            string layoutKey,
+            string layoutUser,
+            BandLayout bandLayout)
+        {
+            var layoutData = JsonSerializer.Serialize(bandLayout, _jsonOptions);
+            await layoutApi.UpsertAsync(new LayoutDto
+            {
+                LayoutType = layoutType,
+                LayoutKey = layoutKey,
+                UserName = layoutUser,
+                LayoutData = layoutData
+            });
+        }
+
+        public async Task ResetBandLayoutAsync(
+            string layoutType,
+            string layoutKey,
+            string layoutUser)
+        {
+            await layoutApi.DeleteAsync(layoutType, layoutKey, layoutUser);
+        }
+
+        public Dictionary<string, string> BuildAssignmentsFromLayout(BandLayout layout)
+        {
+            var assignments = new Dictionary<string, string>(StringComparer.OrdinalIgnoreCase);
+            foreach (var band in layout.Bands)
+            {
+                foreach (var column in band.Columns)
+                {
+                    assignments[column] = band.Id;
+                }
+            }
+            return assignments;
+        }
+
+        public BandLayout NormalizeBandLayout(
+            BandLayout? layout,
+            Dictionary<string, ColumnDefinition> columnLookup)
+        {
+            layout ??= new BandLayout();
+            layout.Bands ??= new List<BandDefinition>();
+            layout.ColumnOrder ??= new List<string>();
+            layout.ColumnWidths ??= new Dictionary<string, string?>(StringComparer.OrdinalIgnoreCase);
+
+            foreach (var band in layout.Bands)
+            {
+                if (string.IsNullOrWhiteSpace(band.Id))
+                    band.Id = Guid.NewGuid().ToString("N");
+
+                if (string.IsNullOrWhiteSpace(band.Caption))
+                    band.Caption = "Band";
+
+                band.Columns = band.Columns?.Where(columnLookup.ContainsKey).ToList() ?? new List<string>();
+            }
+
+            return layout;
+        }
+    }
+}

DbFirst.BlazorWebApp/Services/CatalogApiClient.cs

@@ -1,9 +1,8 @@
 using System.Net;
 using System.Net.Http.Json;
-using System.Text.Json;
-using DbFirst.BlazorWasm.Models;
+using DbFirst.BlazorWebApp.Models;
 
-namespace DbFirst.BlazorWasm.Services;
+namespace DbFirst.BlazorWebApp.Services;
 
 public class CatalogApiClient
 {
@@ -79,20 +78,18 @@ public class CatalogApiClient
         }
         catch
         {
-            // ignore parse errors
         }
 
         var status = response.StatusCode;
         var reason = response.ReasonPhrase;
         var body = await response.Content.ReadAsStringAsync();
 
-        string detail = problemDetail;
+        string? detail = problemDetail;
         if (string.IsNullOrWhiteSpace(detail) && !string.IsNullOrWhiteSpace(body))
         {
             detail = body;
         }
 
-        // Friendly overrides
         if (status == HttpStatusCode.Conflict)
         {
             return "Datensatz existiert bereits. Bitte wählen Sie einen anderen Titel.";

DbFirst.BlazorWebApp/Services/DashboardApiClient.cs

@@ -0,0 +1,21 @@
+using System.Net.Http.Json;
+using DbFirst.BlazorWebApp.Models;
+
+namespace DbFirst.BlazorWebApp.Services;
+
+public class DashboardApiClient
+{
+    private readonly HttpClient _httpClient;
+    private const string Endpoint = "api/dashboard/dashboards";
+
+    public DashboardApiClient(HttpClient httpClient)
+    {
+        _httpClient = httpClient;
+    }
+
+    public async Task<List<DashboardInfoDto>> GetAllAsync()
+    {
+        var result = await _httpClient.GetFromJsonAsync<List<DashboardInfoDto>>(Endpoint);
+        return result ?? new List<DashboardInfoDto>();
+    }
+}

DbFirst.BlazorWebApp/Services/LayoutApiClient.cs

@@ -0,0 +1,64 @@
+using System.Net.Http.Json;
+using DbFirst.BlazorWebApp.Models;
+
+namespace DbFirst.BlazorWebApp.Services;
+
+public class LayoutApiClient
+{
+    private readonly HttpClient _httpClient;
+    private const string Endpoint = "api/layouts";
+
+    public LayoutApiClient(HttpClient httpClient)
+    {
+        _httpClient = httpClient;
+    }
+
+    public async Task<LayoutDto?> GetAsync(string layoutType, string layoutKey, string userName)
+    {
+        var url = $"{Endpoint}?layoutType={Uri.EscapeDataString(layoutType)}&layoutKey={Uri.EscapeDataString(layoutKey)}&userName={Uri.EscapeDataString(userName)}";
+        var response = await _httpClient.GetAsync(url);
+        if (response.StatusCode == System.Net.HttpStatusCode.NotFound)
+        {
+            return null;
+        }
+
+        response.EnsureSuccessStatusCode();
+        return await response.Content.ReadFromJsonAsync<LayoutDto>();
+    }
+
+    public async Task<LayoutDto> UpsertAsync(LayoutDto dto)
+    {
+        var response = await _httpClient.PostAsJsonAsync(Endpoint, dto);
+        if (!response.IsSuccessStatusCode)
+        {
+            var detail = await ReadErrorAsync(response);
+            throw new InvalidOperationException(detail);
+        }
+
+        var payload = await response.Content.ReadFromJsonAsync<LayoutDto>();
+        return payload ?? dto;
+    }
+
+    private static async Task<string> ReadErrorAsync(HttpResponseMessage response)
+    {
+        var body = await response.Content.ReadAsStringAsync();
+        if (!string.IsNullOrWhiteSpace(body))
+        {
+            return body;
+        }
+
+        return $"{(int)response.StatusCode} {response.ReasonPhrase}".Trim();
+    }
+
+    public async Task DeleteAsync(string layoutType, string layoutKey, string userName)
+    {
+        var url = $"{Endpoint}?layoutType={Uri.EscapeDataString(layoutType)}&layoutKey={Uri.EscapeDataString(layoutKey)}&userName={Uri.EscapeDataString(userName)}";
+        var response = await _httpClient.DeleteAsync(url);
+        if (response.StatusCode == System.Net.HttpStatusCode.NotFound)
+        {
+            return;
+        }
+
+        response.EnsureSuccessStatusCode();
+    }
+}

DbFirst.BlazorWebApp/Services/MassDataApiClient.cs

@@ -0,0 +1,63 @@
+using System.Net.Http.Json;
+using DbFirst.BlazorWebApp.Models;
+
+namespace DbFirst.BlazorWebApp.Services;
+
+public class MassDataApiClient
+{
+    private readonly HttpClient _httpClient;
+    private const string Endpoint = "api/massdata";
+
+    public MassDataApiClient(HttpClient httpClient)
+    {
+        _httpClient = httpClient;
+    }
+
+    public async Task<int> GetCountAsync()
+    {
+        var result = await _httpClient.GetFromJsonAsync<int?>("api/massdata/count");
+        return result ?? 0;
+    }
+
+    public async Task<List<MassDataReadDto>> GetAllAsync(int? skip, int? take)
+    {
+        var query = new List<string>();
+        if (skip.HasValue)
+        {
+            query.Add($"skip={skip.Value}");
+        }
+        if (take.HasValue)
+        {
+            query.Add($"take={take.Value}");
+        }
+
+        var url = query.Count == 0 ? Endpoint : $"{Endpoint}?{string.Join("&", query)}";
+        var result = await _httpClient.GetFromJsonAsync<List<MassDataReadDto>>(url);
+        return result ?? new List<MassDataReadDto>();
+    }
+
+    public async Task<MassDataReadDto> UpsertAsync(MassDataWriteDto dto)
+    {
+        var response = await _httpClient.PostAsJsonAsync($"{Endpoint}/upsert", dto);
+        response.EnsureSuccessStatusCode();
+        var payload = await response.Content.ReadFromJsonAsync<MassDataReadDto>();
+        return payload ?? new MassDataReadDto();
+    }
+
+    public async Task<MassDataReadDto?> GetByCustomerNameAsync(string customerName)
+    {
+        if (string.IsNullOrWhiteSpace(customerName))
+        {
+            return null;
+        }
+
+        var response = await _httpClient.GetAsync($"{Endpoint}/{Uri.EscapeDataString(customerName)}");
+        if (response.StatusCode == System.Net.HttpStatusCode.NotFound)
+        {
+            return null;
+        }
+
+        response.EnsureSuccessStatusCode();
+        return await response.Content.ReadFromJsonAsync<MassDataReadDto>();
+    }
+}

DbFirst.BlazorWebApp/Services/ThemeState.cs

@@ -0,0 +1,35 @@
+using DevExpress.Blazor;
+
+namespace DbFirst.BlazorWebApp.Services;
+
+public class ThemeState
+{
+    private readonly IThemeChangeService themeChangeService;
+
+    public ThemeState(IThemeChangeService themeChangeService)
+    {
+        this.themeChangeService = themeChangeService;
+    }
+
+    public bool IsDarkMode { get; private set; }
+
+    public event Action? OnChange;
+
+    public void SetDarkMode(bool isDarkMode)
+    {
+        if (IsDarkMode == isDarkMode)
+        {
+            return;
+        }
+
+        IsDarkMode = isDarkMode;
+        var theme = Themes.Fluent.Clone(properties =>
+        {
+            properties.Mode = isDarkMode ? ThemeMode.Dark : ThemeMode.Light;
+            properties.ApplyToPageElements = true;
+        });
+
+        themeChangeService.SetTheme(theme);
+        OnChange?.Invoke();
+    }
+}

DbFirst.BlazorWebApp/Services/TimeApiClient.cs

@@ -0,0 +1,27 @@
+using System.Net.Http.Json;
+
+namespace DbFirst.BlazorWebApp.Services;
+
+public class TimeApiClient
+{
+    private readonly HttpClient _httpClient;
+    private const string Endpoint = "api/time";
+
+    public TimeApiClient(HttpClient httpClient)
+    {
+        _httpClient = httpClient;
+    }
+
+    public async Task<DateTime?> InsertAndGetLastAsync()
+    {
+        var response = await _httpClient.PostAsync(Endpoint, null);
+        response.EnsureSuccessStatusCode();
+        var result = await response.Content.ReadFromJsonAsync<TimeResponse>();
+        return result?.Now;
+    }
+
+    private sealed class TimeResponse
+    {
+        public DateTime? Now { get; set; }
+    }
+}

DbFirst.BlazorWebApp/appsettings.Development.json

@@ -0,0 +1,9 @@
+{
+  "Logging": {
+    "LogLevel": {
+      "Default": "Information",
+      "Microsoft.AspNetCore": "Warning"
+    }
+  },
+  "ApiBaseUrl": "https://localhost:7204/"
+}

DbFirst.BlazorWebApp/appsettings.json

@@ -0,0 +1,10 @@
+{
+  "Logging": {
+    "LogLevel": {
+      "Default": "Information",
+      "Microsoft.AspNetCore": "Warning"
+    }
+  },
+  "ApiBaseUrl": "https://localhost:7204/",
+  "AllowedHosts": "*"
+}

DbFirst.BlazorWebApp/wwwroot/app.css

@@ -0,0 +1,187 @@
+:root {
+    --global-size: 16px;
+}
+
+html, body {
+    font-family: 'Helvetica Neue', Helvetica, Arial, sans-serif;
+    font-size: var(--global-size);
+}
+
+/* Theme-Variablen */
+.app-light {
+    --band-editor-bg: #f8f9fa;
+    --band-editor-border: #dee2e6;
+    --band-toggle-hover-bg: #e9ecef;
+    --grid-stripe-bg: rgba(0, 0, 0, 0.03);
+}
+
+.app-dark {
+    background-color: #1b1b1b;
+    color: #f1f1f1;
+    --band-editor-bg: #2d2d2d;
+    --band-editor-border: #444444;
+    --band-toggle-hover-bg: #3a3a3a;
+    --grid-stripe-bg: rgba(255, 255, 255, 0.04);
+}
+
+a, .btn-link {
+    color: #006bb7;
+}
+
+.app-dark a, .app-dark .btn-link {
+    color: #6cb6ff;
+}
+
+.btn-primary {
+    color: #fff;
+    background-color: #1b6ec2;
+    border-color: #1861ac;
+}
+
+.btn:focus, .btn:active:focus, .btn-link.nav-link:focus, .form-control:focus, .form-check-input:focus {
+    box-shadow: 0 0 0 0.1rem white, 0 0 0 0.25rem #258cfb;
+}
+
+.content {
+    padding-top: 1.1rem;
+}
+
+h1:focus {
+    outline: none;
+}
+
+.valid.modified:not([type=checkbox]) {
+    outline: 1px solid #26b050;
+}
+
+.invalid {
+    outline: 1px solid #e50000;
+}
+
+.validation-message {
+    color: #e50000;
+}
+
+.blazor-error-boundary {
+    background: url(data:image/svg+xml;base64,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) no-repeat 1rem/1.8rem, #b32121;
+    padding: 1rem 1rem 1rem 3.7rem;
+    color: white;
+}
+
+    .blazor-error-boundary::after {
+        content: "An error has occurred."
+    }
+
+.darker-border-checkbox.form-check-input {
+    border-color: #929292;
+}
+
+/* Grid Band-Editor */
+.band-editor {
+    margin-top: 4px;
+    margin-bottom: 16px;
+    border: 1px solid var(--band-editor-border);
+    border-radius: 4px;
+    background-color: var(--band-editor-bg);
+    overflow: hidden;
+}
+
+.band-editor-toggle {
+    display: flex;
+    align-items: center;
+    gap: 8px;
+    width: 100%;
+    padding: 8px 12px;
+    background: none;
+    border: none;
+    cursor: pointer;
+    font-size: inherit;
+    color: inherit;
+    text-align: left;
+}
+
+    .band-editor-toggle:hover {
+        background-color: var(--band-toggle-hover-bg);
+    }
+
+.band-editor-toggle-icon {
+    font-size: 0.7rem;
+    transition: transform 0.2s ease;
+    display: inline-block;
+}
+
+    .band-editor-toggle-icon.expanded {
+        transform: rotate(90deg);
+    }
+
+.band-editor-body {
+    display: flex;
+    flex-direction: column;
+    gap: 12px;
+    padding: 0 12px 12px 12px;
+}
+
+.band-controls {
+    display: flex;
+    flex-wrap: wrap;
+    gap: 8px;
+    align-items: center;
+}
+
+.band-row {
+    display: flex;
+    gap: 8px;
+    align-items: center;
+}
+
+.band-columns {
+    max-width: 720px;
+    margin-top: 4px;
+}
+
+.grid-section {
+    margin-top: 4px;
+}
+
+/* Grid Zebra-Striping */
+dxbl-grid tbody tr:nth-child(even) td {
+    background-color: var(--grid-stripe-bg) !important;
+}
+
+/* MassData-spezifisch */
+.page-size-selector {
+    display: flex;
+    align-items: center;
+    gap: 8px;
+    flex-wrap: nowrap;
+    margin-bottom: 12px;
+}
+
+.page-size-label {
+    white-space: nowrap;
+}
+
+.page-size-combo {
+    width: 13ch;
+    min-width: 13ch;
+    max-width: 13ch;
+}
+
+    .page-size-combo input {
+        text-align: left;
+    }
+
+.pager-container {
+    display: flex;
+    justify-content: center;
+    margin-top: 12px;
+    margin-bottom: 16px;
+}
+
+/* Lade-Spinner */
+.loading-container {
+    min-height: 160px;
+    display: flex;
+    align-items: center;
+    justify-content: center;
+}

DbFirst.BlazorWebApp/wwwroot/js/size-manager.js

@@ -0,0 +1,3 @@
+window.setSize = function (fontSize) {
+    document.documentElement.style.setProperty('--global-size', fontSize);
+};

DbFirst.Domain/Entities/Massdata.cs

@@ -0,0 +1,12 @@
+namespace DbFirst.Domain.Entities;
+
+public class Massdata
+{
+    public int Id { get; set; }
+    public string CustomerName { get; set; } = string.Empty;
+    public decimal Amount { get; set; }
+    public string Category { get; set; } = string.Empty;
+    public bool StatusFlag { get; set; }
+    public DateTime AddedWhen { get; set; }
+    public DateTime? ChangedWhen { get; set; }
+}