Refactor grids to use DxGrid popup editing

Modernize CatalogsGrid.razor and MassDataGrid.razor to use DevExpress DxGrid's built-in popup editing with EditFormTemplate. Remove custom EditForm panels and manual editing state logic. Move CRUD operations and validation to grid event handlers. Add field-level validation and error display for catalogs. Update grid columns, add command columns, and set audit fields to read-only. Only editing is allowed in MassDataGrid; deletion is disabled. Streamline code and UI for improved maintainability and user experience.

DbFirst.BlazorWasm/Components/CatalogsGrid.razor

@@ -1,3 +1,4 @@
+@using Microsoft.AspNetCore.Components.Forms
 @inject CatalogApiClient Api
 
 <style>
@@ -44,6 +45,9 @@
         background-position: right 0.5rem center;
         background-size: 0.9rem;
     }
+    .catalog-edit-popup {
+        min-width: 720px;
+    }
 </style>
 
 @if (!string.IsNullOrWhiteSpace(errorMessage))
@@ -55,41 +59,6 @@ else if (!string.IsNullOrWhiteSpace(infoMessage))
     <div class="alert alert-success" role="alert">@infoMessage</div>
 }
 
-<div class="mb-3">
-    <DxButton RenderStyle="ButtonRenderStyle.Primary" Click="@StartCreate">Neuen Eintrag anlegen</DxButton>
-</div>
-
-@if (showForm)
-{
-    <div class="action-panel">
-        <EditForm Model="formModel" OnValidSubmit="HandleSubmit" Context="editCtx">
-            <DxFormLayout ColCount="2">
-                <DxFormLayoutItem Caption="Titel" Context="itemCtx">
-                    <DxTextBox @bind-Text="formModel.CatTitle" Enabled="@(isEditing ? formModel.UpdateProcedure != 0 : true)" />
-                </DxFormLayoutItem>
-                <DxFormLayoutItem Caption="Kennung" Context="itemCtx">
-                    <DxTextBox @bind-Text="formModel.CatString" />
-                </DxFormLayoutItem>
-                @if (isEditing)
-                {
-                    <DxFormLayoutItem Caption="Update-Prozedur" Context="itemCtx">
-                        <DxComboBox Data="@procedureOptions"
-                                    TextFieldName="Text"
-                                    ValueFieldName="Value"
-                                    @bind-Value="formModel.UpdateProcedure" />
-                    </DxFormLayoutItem>
-                }
-                <DxFormLayoutItem Caption=" " Context="itemCtx">
-                    <DxStack Orientation="Orientation.Horizontal" Spacing="8">
-                        <DxButton RenderStyle="ButtonRenderStyle.Success" ButtonType="ButtonType.Submit" SubmitFormOnClick="true" Context="btnCtx">@((isEditing ? "Speichern" : "Anlegen"))</DxButton>
-                        <DxButton RenderStyle="ButtonRenderStyle.Secondary" Click="@CancelEdit" Context="btnCtx">Abbrechen</DxButton>
-                    </DxStack>
-                </DxFormLayoutItem>
-            </DxFormLayout>
-        </EditForm>
-    </div>
-}
-
 @if (isLoading)
 {
     <p><em>Lade Daten...</em></p>
@@ -101,68 +70,61 @@ else if (items.Count == 0)
 else
 {
     <div class="grid-section">
-        <DxGrid Data="@items" TItem="CatalogReadDto" KeyFieldName="@nameof(CatalogReadDto.Guid)" ShowFilterRow="true" PageSize="10" CssClass="mb-4 catalog-grid">
+        <DxGrid Data="@items"
+                TItem="CatalogReadDto"
+                KeyFieldName="@nameof(CatalogReadDto.Guid)"
+                ShowFilterRow="true"
+                PageSize="10"
+                CssClass="mb-4 catalog-grid"
+                EditMode="GridEditMode.PopupEditForm"
+                PopupEditFormCssClass="catalog-edit-popup"
+                CustomizeEditModel="OnCustomizeEditModel"
+                EditModelSaving="OnEditModelSaving"
+                DataItemDeleting="OnDataItemDeleting">
             <Columns>
-                <DxGridDataColumn FieldName="@nameof(CatalogReadDto.Guid)" Caption="Id" Width="140px" SortIndex="0" SortOrder="GridColumnSortOrder.Ascending">
+                <DxGridCommandColumn Width="120px" />
-                    <FilterRowCellTemplate Context="filter">
+                <DxGridDataColumn FieldName="@nameof(CatalogReadDto.Guid)" Caption="Id" Width="140px" SortIndex="0" SortOrder="GridColumnSortOrder.Ascending" />
-                        <DxTextBox Text="@(filter.FilterRowValue?.ToString())"
+                <DxGridDataColumn FieldName="@nameof(CatalogReadDto.CatTitle)" Caption="Titel" />
-                                   TextChanged="@(value => filter.FilterRowValue = value)"
+                <DxGridDataColumn FieldName="@nameof(CatalogReadDto.CatString)" Caption="String" />
-                                   CssClass="filter-search-input" />
+                <DxGridDataColumn FieldName="@nameof(CatalogReadDto.AddedWho)" Caption="Angelegt von" ReadOnly="true" />
-                    </FilterRowCellTemplate>
+                <DxGridDataColumn FieldName="@nameof(CatalogReadDto.AddedWhen)" Caption="Angelegt am" ReadOnly="true" />
-                </DxGridDataColumn>
+                <DxGridDataColumn FieldName="@nameof(CatalogReadDto.ChangedWho)" Caption="Geändert von" ReadOnly="true" />
-                <DxGridDataColumn FieldName="@nameof(CatalogReadDto.CatTitle)" Caption="Titel">
+                <DxGridDataColumn FieldName="@nameof(CatalogReadDto.ChangedWhen)" Caption="Geändert am" ReadOnly="true" />
-                    <FilterRowCellTemplate Context="filter">
-                        <DxTextBox Text="@(filter.FilterRowValue as string)"
-                                   TextChanged="@(value => filter.FilterRowValue = value)"
-                                   CssClass="filter-search-input" />
-                    </FilterRowCellTemplate>
-                </DxGridDataColumn>
-                <DxGridDataColumn FieldName="@nameof(CatalogReadDto.CatString)" Caption="String">
-                    <FilterRowCellTemplate Context="filter">
-                        <DxTextBox Text="@(filter.FilterRowValue as string)"
-                                   TextChanged="@(value => filter.FilterRowValue = value)"
-                                   CssClass="filter-search-input" />
-                    </FilterRowCellTemplate>
-                </DxGridDataColumn>
-                <DxGridDataColumn FieldName="@nameof(CatalogReadDto.AddedWho)" Caption="Angelegt von">
-                    <FilterRowCellTemplate Context="filter">
-                        <DxTextBox Text="@(filter.FilterRowValue as string)"
-                                   TextChanged="@(value => filter.FilterRowValue = value)"
-                                   CssClass="filter-search-input" />
-                    </FilterRowCellTemplate>
-                </DxGridDataColumn>
-                <DxGridDataColumn FieldName="@nameof(CatalogReadDto.AddedWhen)" Caption="Angelegt am" />
-                <DxGridDataColumn FieldName="@nameof(CatalogReadDto.ChangedWho)" Caption="Geändert von">
-                    <FilterRowCellTemplate Context="filter">
-                        <DxTextBox Text="@(filter.FilterRowValue as string)"
-                                   TextChanged="@(value => filter.FilterRowValue = value)"
-                                   CssClass="filter-search-input" />
-                    </FilterRowCellTemplate>
-                </DxGridDataColumn>
-                <DxGridDataColumn FieldName="@nameof(CatalogReadDto.ChangedWhen)" Caption="Geändert am" />
-                <DxGridDataColumn Caption="" Width="220px" AllowSort="false">
-                    <CellDisplayTemplate Context="cell">
-                        @{ var item = (CatalogReadDto)cell.DataItem; }
-                        <div style="white-space: nowrap;">
-                            <DxButton RenderStyle="ButtonRenderStyle.Secondary" Size="ButtonSize.Small" Click="@(() => StartEdit(item))">Bearbeiten</DxButton>
-                            <DxButton RenderStyle="ButtonRenderStyle.Danger" Size="ButtonSize.Small" Click="@(() => DeleteCatalog(item.Guid))">Löschen</DxButton>
-                        </div>
-                    </CellDisplayTemplate>
-                </DxGridDataColumn>
             </Columns>
+            <EditFormTemplate Context="editFormContext">
+                @{ SetEditContext(editFormContext.EditContext); var editModel = (CatalogEditModel)editFormContext.EditModel; }
+                <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>
+                    <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 CatalogWriteDto formModel = new();
-    private int editingId;
     private bool isLoading;
-    private bool isEditing;
-    private bool showForm;
     private string? errorMessage;
     private string? infoMessage;
+    private EditContext? editContext;
+    private ValidationMessageStore? validationMessageStore;
 
     private readonly List<ProcedureOption> procedureOptions = new()
     {
@@ -175,6 +137,57 @@ else
         await LoadCatalogs();
     }
 
+    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) ||
+            e.FieldIdentifier.FieldName == nameof(CatalogEditModel.CatTitle))
+        {
+            validationMessageStore.Clear();
+            editContext.NotifyValidationStateChanged();
+        }
+    }
+
+    private void OnCustomizeEditModel(GridCustomizeEditModelEventArgs e)
+    {
+        if (e.IsNew)
+        {
+            e.EditModel = new CatalogEditModel();
+            return;
+        }
+
+        var item = (CatalogReadDto)e.DataItem;
+        e.EditModel = new CatalogEditModel
+        {
+            Guid = item.Guid,
+            CatTitle = item.CatTitle,
+            CatString = item.CatString,
+            UpdateProcedure = 0,
+            OriginalCatTitle = item.CatTitle
+        };
+    }
+
     private async Task LoadCatalogs()
     {
         isLoading = true;
@@ -194,88 +207,115 @@ else
         }
     }
 
-    private void StartCreate()
+    private async Task OnEditModelSaving(GridEditModelSavingEventArgs e)
     {
-        formModel = new CatalogWriteDto();
-        editingId = 0;
-        isEditing = false;
-        showForm = true;
-        infoMessage = null;
         errorMessage = null;
-    }
+        infoMessage = null;
 
-    private void StartEdit(CatalogReadDto item)
+        validationMessageStore?.Clear();
-    {
+        editContext?.NotifyValidationStateChanged();
-        formModel = new CatalogWriteDto
+
+        var editModel = (CatalogEditModel)e.EditModel;
+        if (!ValidateEditModel(editModel, e.IsNew))
         {
-            CatTitle = item.CatTitle,
+            e.Cancel = true;
-            CatString = item.CatString,
+            return;
-            UpdateProcedure = 0
+        }
-        };
-        editingId = item.Guid;
-        isEditing = true;
-        showForm = true;
-        infoMessage = null;
-        errorMessage = null;
-    }
 
-    private async Task HandleSubmit()
+        var dto = new CatalogWriteDto
-    {
+        {
-        errorMessage = null;
+            CatTitle = editModel.CatTitle,
-        infoMessage = null;
+            CatString = editModel.CatString,
+            UpdateProcedure = editModel.UpdateProcedure
+        };
 
         try
         {
-            if (isEditing)
+            if (e.IsNew)
             {
-                var updated = await Api.UpdateAsync(editingId, formModel);
+                var created = await Api.CreateAsync(dto);
-                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.";
+                    if (!string.IsNullOrWhiteSpace(created.Error))
+                    {
+                        AddValidationError(editModel, nameof(CatalogEditModel.CatTitle), created.Error);
+                    }
+                    else
+                    {
+                        errorMessage = "Anlegen fehlgeschlagen.";
+                    }
+
+                    e.Cancel = true;
                     return;
                 }
 
                 infoMessage = "Katalog angelegt.";
             }
+            else
+            {
+                var updated = await Api.UpdateAsync(editModel.Guid, dto);
+                if (!updated.Success)
+                {
+                    errorMessage = updated.Error ?? "Aktualisierung fehlgeschlagen.";
+                    e.Cancel = true;
+                    return;
+                }
+
+                infoMessage = "Katalog aktualisiert.";
+            }
 
-            showForm = false;
             await LoadCatalogs();
         }
         catch (Exception ex)
         {
             errorMessage = $"Fehler beim Speichern: {ex.Message}";
+            e.Cancel = true;
         }
     }
 
-    private void CancelEdit()
+    private void AddValidationError(CatalogEditModel editModel, string fieldName, string message)
     {
-        showForm = false;
+        if (editContext == null || validationMessageStore == null)
-        infoMessage = null;
+        {
-        errorMessage = null;
+            return;
+        }
+
+        var field = new FieldIdentifier(editModel, fieldName);
+        validationMessageStore.Add(field, message);
+        editContext.NotifyValidationStateChanged();
     }
 
-    private async Task DeleteCatalog(int id)
+    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(id);
+            var deleted = await Api.DeleteAsync(item.Guid);
             if (!deleted.Success)
             {
                 errorMessage = deleted.Error ?? "Löschen fehlgeschlagen.";
+                e.Cancel = true;
                 return;
             }
 
@@ -285,9 +325,19 @@ else
         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;
+    }
+
     private sealed class ProcedureOption
     {
         public int Value { get; set; }

DbFirst.BlazorWasm/Components/MassDataGrid.razor

@@ -61,38 +61,6 @@ else if (!string.IsNullOrWhiteSpace(infoMessage))
     <div class="alert alert-success" role="alert">@infoMessage</div>
 }
 
-<div class="mb-3">
-    <DxButton RenderStyle="ButtonRenderStyle.Primary" Click="@StartCreate">Neuen Eintrag anlegen</DxButton>
-</div>
-
-@if (showForm)
-{
-    <div class="action-panel">
-        <EditForm Model="formModel" OnValidSubmit="HandleSubmit" Context="editCtx">
-            <DxFormLayout ColCount="2">
-                <DxFormLayoutItem Caption="CustomerName" Context="itemCtx">
-                    <DxTextBox @bind-Text="formModel.CustomerName" />
-                </DxFormLayoutItem>
-                <DxFormLayoutItem Caption="Amount" Context="itemCtx">
-                    <DxTextBox @bind-Text="amountText" />
-                </DxFormLayoutItem>
-                <DxFormLayoutItem Caption="Category" Context="itemCtx">
-                    <DxTextBox @bind-Text="formModel.Category" ReadOnly="true" />
-                </DxFormLayoutItem>
-                <DxFormLayoutItem Caption="Status" Context="itemCtx">
-                    <DxCheckBox @bind-Checked="formModel.StatusFlag" ReadOnly="true" />
-                </DxFormLayoutItem>
-                <DxFormLayoutItem Caption=" " Context="itemCtx">
-                    <DxStack Orientation="Orientation.Horizontal" Spacing="8">
-                        <DxButton RenderStyle="ButtonRenderStyle.Success" ButtonType="ButtonType.Submit" SubmitFormOnClick="true" Context="btnCtx">Speichern</DxButton>
-                        <DxButton RenderStyle="ButtonRenderStyle.Secondary" Click="@CancelEdit" Context="btnCtx">Abbrechen</DxButton>
-                    </DxStack>
-                </DxFormLayoutItem>
-            </DxFormLayout>
-        </EditForm>
-    </div>
-}
-
 @if (isLoading)
 {
     <p><em>Lade Daten...</em></p>
@@ -104,9 +72,21 @@ else if (items.Count == 0)
 else
 {
     <div class="grid-section">
-        <DxGrid Data="@items" TItem="MassDataReadDto" KeyFieldName="@nameof(MassDataReadDto.Id)" ShowFilterRow="true" ShowGroupPanel="true" AllowColumnResize="true" PagerVisible="false" PageSize="100" CssClass="mb-3 massdata-grid">
+        <DxGrid Data="@items"
+                TItem="MassDataReadDto"
+                KeyFieldName="@nameof(MassDataReadDto.Id)"
+                ShowFilterRow="true"
+                ShowGroupPanel="true"
+                AllowColumnResize="true"
+                PagerVisible="false"
+                PageSize="100"
+                CssClass="mb-3 massdata-grid"
+                EditMode="GridEditMode.PopupEditForm"
+                EditModelSaving="OnEditModelSaving"
+                DataItemDeleting="OnDataItemDeleting">
             <Columns>
-                <DxGridDataColumn FieldName="@nameof(MassDataReadDto.Id)" Caption="Id" Width="90px">
+                <DxGridCommandColumn Width="120px" NewButtonVisible="false" />
+                <DxGridDataColumn FieldName="@nameof(MassDataReadDto.Id)" Caption="Id" Width="90px" ReadOnly="true">
                     <FilterRowCellTemplate Context="filter">
                         <DxTextBox Text="@(filter.FilterRowValue?.ToString())"
                                    TextChanged="@(value => filter.FilterRowValue = value)"
@@ -127,44 +107,51 @@ else
                                    CssClass="filter-search-input" />
                     </FilterRowCellTemplate>
                 </DxGridDataColumn>
-                <DxGridDataColumn FieldName="@nameof(MassDataReadDto.Category)" Caption="Category">
+                <DxGridDataColumn FieldName="@nameof(MassDataReadDto.Category)" Caption="Category" ReadOnly="true">
                     <FilterRowCellTemplate Context="filter">
                         <DxTextBox Text="@(filter.FilterRowValue as string)"
                                    TextChanged="@(value => filter.FilterRowValue = value)"
                                    CssClass="filter-search-input" />
                     </FilterRowCellTemplate>
                 </DxGridDataColumn>
-                <DxGridDataColumn FieldName="@nameof(MassDataReadDto.StatusFlag)" Caption="Status">
+                <DxGridDataColumn FieldName="@nameof(MassDataReadDto.StatusFlag)" Caption="Status" ReadOnly="true">
                     <FilterRowCellTemplate Context="filter">
                         <DxTextBox Text="@(filter.FilterRowValue?.ToString())"
                                    TextChanged="@(value => filter.FilterRowValue = value)"
                                    CssClass="filter-search-input" />
                     </FilterRowCellTemplate>
                 </DxGridDataColumn>
-                <DxGridDataColumn FieldName="@nameof(MassDataReadDto.AddedWhen)" Caption="Added">
+                <DxGridDataColumn FieldName="@nameof(MassDataReadDto.AddedWhen)" Caption="Added" ReadOnly="true">
                     <FilterRowCellTemplate Context="filter">
                         <DxTextBox Text="@(filter.FilterRowValue?.ToString())"
                                    TextChanged="@(value => filter.FilterRowValue = value)"
                                    CssClass="filter-search-input" />
                     </FilterRowCellTemplate>
                 </DxGridDataColumn>
-                <DxGridDataColumn FieldName="@nameof(MassDataReadDto.ChangedWhen)" Caption="Changed">
+                <DxGridDataColumn FieldName="@nameof(MassDataReadDto.ChangedWhen)" Caption="Changed" ReadOnly="true">
                     <FilterRowCellTemplate Context="filter">
                         <DxTextBox Text="@(filter.FilterRowValue?.ToString())"
                                    TextChanged="@(value => filter.FilterRowValue = value)"
                                    CssClass="filter-search-input" />
                     </FilterRowCellTemplate>
                 </DxGridDataColumn>
-                <DxGridDataColumn Caption="" Width="220px" AllowSort="false">
-                    <CellDisplayTemplate Context="cell">
-                        @{ var item = (MassDataReadDto)cell.DataItem; }
-                        <div style="white-space: nowrap;">
-                            <DxButton RenderStyle="ButtonRenderStyle.Secondary" Size="ButtonSize.Small" Click="@(() => StartEdit(item))">Bearbeiten</DxButton>
-                            <DxButton RenderStyle="ButtonRenderStyle.Danger" Size="ButtonSize.Small" Click="@ShowDeleteNotReady">Löschen</DxButton>
-                        </div>
-                    </CellDisplayTemplate>
-                </DxGridDataColumn>
             </Columns>
+            <EditFormTemplate Context="editFormContext">
+                <DxFormLayout>
+                    <DxFormLayoutItem Caption="CustomerName">
+                        @editFormContext.GetEditor(nameof(MassDataReadDto.CustomerName))
+                    </DxFormLayoutItem>
+                    <DxFormLayoutItem Caption="Amount">
+                        @editFormContext.GetEditor(nameof(MassDataReadDto.Amount))
+                    </DxFormLayoutItem>
+                    <DxFormLayoutItem Caption="Category">
+                        @editFormContext.GetEditor(nameof(MassDataReadDto.Category))
+                    </DxFormLayoutItem>
+                    <DxFormLayoutItem Caption="Status">
+                        @editFormContext.GetEditor(nameof(MassDataReadDto.StatusFlag))
+                    </DxFormLayoutItem>
+                </DxFormLayout>
+            </EditFormTemplate>
         </DxGrid>
 
         <div class="pager-container">
@@ -176,10 +163,7 @@ else
 @code {
     private const int PageSize = 100;
     private List<MassDataReadDto> items = new();
-    private MassDataWriteDto formModel = new();
-    private string amountText = string.Empty;
     private bool isLoading;
-    private bool showForm;
     private string? errorMessage;
     private string? infoMessage;
     private int pageIndex;
@@ -219,61 +203,38 @@ else
         await LoadPage(index);
     }
 
-    private void StartCreate()
+    private async Task OnEditModelSaving(GridEditModelSavingEventArgs e)
     {
-        infoMessage = "Anlegen ist aktuell noch nicht verfügbar.";
+        errorMessage = null;
-    }
+        infoMessage = null;
 
-    private void StartEdit(MassDataReadDto item)
+        var editModel = (MassDataReadDto)e.EditModel;
-    {
+        var dto = new MassDataWriteDto
-        formModel = new MassDataWriteDto
         {
-            CustomerName = item.CustomerName,
+            CustomerName = editModel.CustomerName,
-            Amount = item.Amount,
+            Amount = editModel.Amount,
-            Category = item.Category,
+            Category = editModel.Category,
-            StatusFlag = item.StatusFlag
+            StatusFlag = editModel.StatusFlag
         };
-        amountText = item.Amount.ToString("0.00");
-        showForm = true;
-        infoMessage = null;
-        errorMessage = null;
-    }
-
-    private async Task HandleSubmit()
-    {
-        errorMessage = null;
-        infoMessage = null;
-
-        if (!decimal.TryParse(amountText, out var amount))
-        {
-            errorMessage = "Amount ist ungültig.";
-            return;
-        }
-
-        formModel.Amount = amount;
 
         try
         {
-            await Api.UpsertAsync(formModel);
+            await Api.UpsertAsync(dto);
             infoMessage = "MassData aktualisiert.";
-            showForm = false;
             await LoadPage(pageIndex);
         }
         catch (Exception ex)
         {
             errorMessage = $"Fehler beim Speichern: {ex.Message}";
+            e.Cancel = true;
         }
     }
 
-    private void CancelEdit()
+    private Task OnDataItemDeleting(GridDataItemDeletingEventArgs e)
     {
-        showForm = false;
-        infoMessage = null;
         errorMessage = null;
-    }
-
-    private void ShowDeleteNotReady()
-    {
         infoMessage = "Löschen ist aktuell noch nicht verfügbar.";
+        e.Cancel = true;
+        return Task.CompletedTask;
     }
 }

DbFirst.BlazorWebApp/Components/CatalogsGrid.razor

@@ -1,8 +1,12 @@
+@using Microsoft.AspNetCore.Components.Forms
 @inject CatalogApiClient Api
 
 <style>
     .action-panel { margin-bottom: 16px; }
     .grid-section { margin-top: 12px; }
+    .catalog-edit-popup {
+        min-width: 720px;
+    }
 </style>
 
 @if (!string.IsNullOrWhiteSpace(errorMessage))
@@ -14,41 +18,6 @@ else if (!string.IsNullOrWhiteSpace(infoMessage))
     <div class="alert alert-success" role="alert">@infoMessage</div>
 }
 
-<div class="mb-3">
-    <DxButton RenderStyle="ButtonRenderStyle.Primary" Click="@StartCreate">Neuen Eintrag anlegen</DxButton>
-</div>
-
-@if (showForm)
-{
-    <div class="action-panel">
-        <EditForm Model="formModel" OnValidSubmit="HandleSubmit" Context="editCtx">
-            <DxFormLayout ColCount="2">
-                <DxFormLayoutItem Caption="Titel" Context="itemCtx">
-                    <DxTextBox @bind-Text="formModel.CatTitle" Enabled="@(isEditing ? formModel.UpdateProcedure != 0 : true)" />
-                </DxFormLayoutItem>
-                <DxFormLayoutItem Caption="Kennung" Context="itemCtx">
-                    <DxTextBox @bind-Text="formModel.CatString" />
-                </DxFormLayoutItem>
-                @if (isEditing)
-                {
-                    <DxFormLayoutItem Caption="Update-Prozedur" Context="itemCtx">
-                        <DxComboBox Data="@procedureOptions"
-                                    TextFieldName="Text"
-                                    ValueFieldName="Value"
-                                    @bind-Value="formModel.UpdateProcedure" />
-                    </DxFormLayoutItem>
-                }
-                <DxFormLayoutItem Caption=" " Context="itemCtx">
-                    <DxStack Orientation="Orientation.Horizontal" Spacing="8">
-                        <DxButton RenderStyle="ButtonRenderStyle.Success" ButtonType="ButtonType.Submit" SubmitFormOnClick="true" Context="btnCtx">@((isEditing ? "Speichern" : "Anlegen"))</DxButton>
-                        <DxButton RenderStyle="ButtonRenderStyle.Secondary" Click="@CancelEdit" Context="btnCtx">Abbrechen</DxButton>
-                    </DxStack>
-                </DxFormLayoutItem>
-            </DxFormLayout>
-        </EditForm>
-    </div>
-}
-
 @if (isLoading)
 {
     <p><em>Lade Daten...</em></p>
@@ -60,38 +29,61 @@ else if (items.Count == 0)
 else
 {
     <div class="grid-section">
-        <DxGrid Data="@items" TItem="CatalogReadDto" KeyFieldName="@nameof(CatalogReadDto.Guid)" ShowFilterRow="true" PageSize="10" CssClass="mb-4 catalog-grid">
+        <DxGrid Data="@items"
+                TItem="CatalogReadDto"
+                KeyFieldName="@nameof(CatalogReadDto.Guid)"
+                ShowFilterRow="true"
+                PageSize="10"
+                CssClass="mb-4 catalog-grid"
+                EditMode="GridEditMode.PopupEditForm"
+                PopupEditFormCssClass="catalog-edit-popup"
+                CustomizeEditModel="OnCustomizeEditModel"
+                EditModelSaving="OnEditModelSaving"
+                DataItemDeleting="OnDataItemDeleting">
             <Columns>
+                <DxGridCommandColumn Width="120px" />
                 <DxGridDataColumn FieldName="@nameof(CatalogReadDto.Guid)" Caption="Id" Width="140px" SortIndex="0" SortOrder="GridColumnSortOrder.Ascending" />
                 <DxGridDataColumn FieldName="@nameof(CatalogReadDto.CatTitle)" Caption="Titel" />
                 <DxGridDataColumn FieldName="@nameof(CatalogReadDto.CatString)" Caption="String" />
-                <DxGridDataColumn FieldName="@nameof(CatalogReadDto.AddedWho)" Caption="Angelegt von" />
+                <DxGridDataColumn FieldName="@nameof(CatalogReadDto.AddedWho)" Caption="Angelegt von" ReadOnly="true" />
-                <DxGridDataColumn FieldName="@nameof(CatalogReadDto.AddedWhen)" Caption="Angelegt am" />
+                <DxGridDataColumn FieldName="@nameof(CatalogReadDto.AddedWhen)" Caption="Angelegt am" ReadOnly="true" />
-                <DxGridDataColumn FieldName="@nameof(CatalogReadDto.ChangedWho)" Caption="Geändert von" />
+                <DxGridDataColumn FieldName="@nameof(CatalogReadDto.ChangedWho)" Caption="Geändert von" ReadOnly="true" />
-                <DxGridDataColumn FieldName="@nameof(CatalogReadDto.ChangedWhen)" Caption="Geändert am" />
+                <DxGridDataColumn FieldName="@nameof(CatalogReadDto.ChangedWhen)" Caption="Geändert am" ReadOnly="true" />
-                <DxGridDataColumn Caption="" Width="220px" AllowSort="false">
-                    <CellDisplayTemplate Context="cell">
-                        @{ var item = (CatalogReadDto)cell.DataItem; }
-                        <div style="white-space: nowrap;">
-                            <DxButton RenderStyle="ButtonRenderStyle.Secondary" Size="ButtonSize.Small" Click="@(() => StartEdit(item))">Bearbeiten</DxButton>
-                            <DxButton RenderStyle="ButtonRenderStyle.Danger" Size="ButtonSize.Small" Click="@(() => DeleteCatalog(item.Guid))">Löschen</DxButton>
-                        </div>
-                    </CellDisplayTemplate>
-                </DxGridDataColumn>
             </Columns>
+            <EditFormTemplate Context="editFormContext">
+                @{ SetEditContext(editFormContext.EditContext); var editModel = (CatalogEditModel)editFormContext.EditModel; }
+                <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>
+                    <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 CatalogWriteDto formModel = new();
-    private int editingId;
     private bool isLoading;
-    private bool isEditing;
-    private bool showForm;
     private string? errorMessage;
     private string? infoMessage;
+    private EditContext? editContext;
+    private ValidationMessageStore? validationMessageStore;
 
     private readonly List<ProcedureOption> procedureOptions = new()
     {
@@ -104,6 +96,57 @@ else
         await LoadCatalogs();
     }
 
+    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) ||
+            e.FieldIdentifier.FieldName == nameof(CatalogEditModel.CatTitle))
+        {
+            validationMessageStore.Clear();
+            editContext.NotifyValidationStateChanged();
+        }
+    }
+
+    private void OnCustomizeEditModel(GridCustomizeEditModelEventArgs e)
+    {
+        if (e.IsNew)
+        {
+            e.EditModel = new CatalogEditModel();
+            return;
+        }
+
+        var item = (CatalogReadDto)e.DataItem;
+        e.EditModel = new CatalogEditModel
+        {
+            Guid = item.Guid,
+            CatTitle = item.CatTitle,
+            CatString = item.CatString,
+            UpdateProcedure = 0,
+            OriginalCatTitle = item.CatTitle
+        };
+    }
+
     private async Task LoadCatalogs()
     {
         isLoading = true;
@@ -123,88 +166,115 @@ else
         }
     }
 
-    private void StartCreate()
+    private async Task OnEditModelSaving(GridEditModelSavingEventArgs e)
     {
-        formModel = new CatalogWriteDto();
-        editingId = 0;
-        isEditing = false;
-        showForm = true;
-        infoMessage = null;
         errorMessage = null;
-    }
+        infoMessage = null;
 
-    private void StartEdit(CatalogReadDto item)
+        validationMessageStore?.Clear();
-    {
+        editContext?.NotifyValidationStateChanged();
-        formModel = new CatalogWriteDto
+
+        var editModel = (CatalogEditModel)e.EditModel;
+        if (!ValidateEditModel(editModel, e.IsNew))
         {
-            CatTitle = item.CatTitle,
+            e.Cancel = true;
-            CatString = item.CatString,
+            return;
-            UpdateProcedure = 0
+        }
-        };
-        editingId = item.Guid;
-        isEditing = true;
-        showForm = true;
-        infoMessage = null;
-        errorMessage = null;
-    }
 
-    private async Task HandleSubmit()
+        var dto = new CatalogWriteDto
-    {
+        {
-        errorMessage = null;
+            CatTitle = editModel.CatTitle,
-        infoMessage = null;
+            CatString = editModel.CatString,
+            UpdateProcedure = editModel.UpdateProcedure
+        };
 
         try
         {
-            if (isEditing)
+            if (e.IsNew)
             {
-                var updated = await Api.UpdateAsync(editingId, formModel);
+                var created = await Api.CreateAsync(dto);
-                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.";
+                    if (!string.IsNullOrWhiteSpace(created.Error))
+                    {
+                        AddValidationError(editModel, nameof(CatalogEditModel.CatTitle), created.Error);
+                    }
+                    else
+                    {
+                        errorMessage = "Anlegen fehlgeschlagen.";
+                    }
+
+                    e.Cancel = true;
                     return;
                 }
 
                 infoMessage = "Katalog angelegt.";
             }
+            else
+            {
+                var updated = await Api.UpdateAsync(editModel.Guid, dto);
+                if (!updated.Success)
+                {
+                    errorMessage = updated.Error ?? "Aktualisierung fehlgeschlagen.";
+                    e.Cancel = true;
+                    return;
+                }
+
+                infoMessage = "Katalog aktualisiert.";
+            }
 
-            showForm = false;
             await LoadCatalogs();
         }
         catch (Exception ex)
         {
             errorMessage = $"Fehler beim Speichern: {ex.Message}";
+            e.Cancel = true;
         }
     }
 
-    private void CancelEdit()
+    private void AddValidationError(CatalogEditModel editModel, string fieldName, string message)
     {
-        showForm = false;
+        if (editContext == null || validationMessageStore == null)
-        infoMessage = null;
+        {
-        errorMessage = null;
+            return;
+        }
+
+        var field = new FieldIdentifier(editModel, fieldName);
+        validationMessageStore.Add(field, message);
+        editContext.NotifyValidationStateChanged();
     }
 
-    private async Task DeleteCatalog(int id)
+    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(id);
+            var deleted = await Api.DeleteAsync(item.Guid);
             if (!deleted.Success)
             {
                 errorMessage = deleted.Error ?? "Löschen fehlgeschlagen.";
+                e.Cancel = true;
                 return;
             }
 
@@ -214,9 +284,19 @@ else
         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;
+    }
+
     private sealed class ProcedureOption
     {
         public int Value { get; set; }

DbFirst.BlazorWebApp/Components/MassDataGrid.razor

@@ -61,38 +61,6 @@ else if (!string.IsNullOrWhiteSpace(infoMessage))
     <div class="alert alert-success" role="alert">@infoMessage</div>
 }
 
-<div class="mb-3">
-    <DxButton RenderStyle="ButtonRenderStyle.Primary" Click="@StartCreate">Neuen Eintrag anlegen</DxButton>
-</div>
-
-@if (showForm)
-{
-    <div class="action-panel">
-        <EditForm Model="formModel" OnValidSubmit="HandleSubmit" Context="editCtx">
-            <DxFormLayout ColCount="2">
-                <DxFormLayoutItem Caption="CustomerName" Context="itemCtx">
-                    <DxTextBox @bind-Text="formModel.CustomerName" />
-                </DxFormLayoutItem>
-                <DxFormLayoutItem Caption="Amount" Context="itemCtx">
-                    <DxTextBox @bind-Text="amountText" />
-                </DxFormLayoutItem>
-                <DxFormLayoutItem Caption="Category" Context="itemCtx">
-                    <DxTextBox @bind-Text="formModel.Category" ReadOnly="true" />
-                </DxFormLayoutItem>
-                <DxFormLayoutItem Caption="Status" Context="itemCtx">
-                    <DxCheckBox @bind-Checked="formModel.StatusFlag" ReadOnly="true" />
-                </DxFormLayoutItem>
-                <DxFormLayoutItem Caption=" " Context="itemCtx">
-                    <DxStack Orientation="Orientation.Horizontal" Spacing="8">
-                        <DxButton RenderStyle="ButtonRenderStyle.Success" ButtonType="ButtonType.Submit" SubmitFormOnClick="true" Context="btnCtx">Speichern</DxButton>
-                        <DxButton RenderStyle="ButtonRenderStyle.Secondary" Click="@CancelEdit" Context="btnCtx">Abbrechen</DxButton>
-                    </DxStack>
-                </DxFormLayoutItem>
-            </DxFormLayout>
-        </EditForm>
-    </div>
-}
-
 @if (isLoading)
 {
     <p><em>Lade Daten...</em></p>
@@ -104,9 +72,21 @@ else if (items.Count == 0)
 else
 {
     <div class="grid-section">
-        <DxGrid Data="@items" TItem="MassDataReadDto" KeyFieldName="@nameof(MassDataReadDto.Id)" ShowFilterRow="true" ShowGroupPanel="true" AllowColumnResize="true" PagerVisible="false" PageSize="100" CssClass="mb-3 massdata-grid">
+        <DxGrid Data="@items"
+                TItem="MassDataReadDto"
+                KeyFieldName="@nameof(MassDataReadDto.Id)"
+                ShowFilterRow="true"
+                ShowGroupPanel="true"
+                AllowColumnResize="true"
+                PagerVisible="false"
+                PageSize="100"
+                CssClass="mb-3 massdata-grid"
+                EditMode="GridEditMode.PopupEditForm"
+                EditModelSaving="OnEditModelSaving"
+                DataItemDeleting="OnDataItemDeleting">
             <Columns>
-                <DxGridDataColumn FieldName="@nameof(MassDataReadDto.Id)" Caption="Id" Width="90px">
+                <DxGridCommandColumn Width="120px" NewButtonVisible="false" />
+                <DxGridDataColumn FieldName="@nameof(MassDataReadDto.Id)" Caption="Id" Width="90px" ReadOnly="true">
                     <FilterRowCellTemplate Context="filter">
                         <DxTextBox Text="@(filter.FilterRowValue?.ToString())"
                                    TextChanged="@(value => filter.FilterRowValue = value)"
@@ -127,44 +107,51 @@ else
                                    CssClass="filter-search-input" />
                     </FilterRowCellTemplate>
                 </DxGridDataColumn>
-                <DxGridDataColumn FieldName="@nameof(MassDataReadDto.Category)" Caption="Category">
+                <DxGridDataColumn FieldName="@nameof(MassDataReadDto.Category)" Caption="Category" ReadOnly="true">
                     <FilterRowCellTemplate Context="filter">
                         <DxTextBox Text="@(filter.FilterRowValue as string)"
                                    TextChanged="@(value => filter.FilterRowValue = value)"
                                    CssClass="filter-search-input" />
                     </FilterRowCellTemplate>
                 </DxGridDataColumn>
-                <DxGridDataColumn FieldName="@nameof(MassDataReadDto.StatusFlag)" Caption="Status">
+                <DxGridDataColumn FieldName="@nameof(MassDataReadDto.StatusFlag)" Caption="Status" ReadOnly="true">
                     <FilterRowCellTemplate Context="filter">
                         <DxTextBox Text="@(filter.FilterRowValue?.ToString())"
                                    TextChanged="@(value => filter.FilterRowValue = value)"
                                    CssClass="filter-search-input" />
                     </FilterRowCellTemplate>
                 </DxGridDataColumn>
-                <DxGridDataColumn FieldName="@nameof(MassDataReadDto.AddedWhen)" Caption="Added">
+                <DxGridDataColumn FieldName="@nameof(MassDataReadDto.AddedWhen)" Caption="Added" ReadOnly="true">
                     <FilterRowCellTemplate Context="filter">
                         <DxTextBox Text="@(filter.FilterRowValue?.ToString())"
                                    TextChanged="@(value => filter.FilterRowValue = value)"
                                    CssClass="filter-search-input" />
                     </FilterRowCellTemplate>
                 </DxGridDataColumn>
-                <DxGridDataColumn FieldName="@nameof(MassDataReadDto.ChangedWhen)" Caption="Changed">
+                <DxGridDataColumn FieldName="@nameof(MassDataReadDto.ChangedWhen)" Caption="Changed" ReadOnly="true">
                     <FilterRowCellTemplate Context="filter">
                         <DxTextBox Text="@(filter.FilterRowValue?.ToString())"
                                    TextChanged="@(value => filter.FilterRowValue = value)"
                                    CssClass="filter-search-input" />
                     </FilterRowCellTemplate>
                 </DxGridDataColumn>
-                <DxGridDataColumn Caption="" Width="220px" AllowSort="false">
-                    <CellDisplayTemplate Context="cell">
-                        @{ var item = (MassDataReadDto)cell.DataItem; }
-                        <div style="white-space: nowrap;">
-                            <DxButton RenderStyle="ButtonRenderStyle.Secondary" Size="ButtonSize.Small" Click="@(() => StartEdit(item))">Bearbeiten</DxButton>
-                            <DxButton RenderStyle="ButtonRenderStyle.Danger" Size="ButtonSize.Small" Click="@ShowDeleteNotReady">Löschen</DxButton>
-                        </div>
-                    </CellDisplayTemplate>
-                </DxGridDataColumn>
             </Columns>
+            <EditFormTemplate Context="editFormContext">
+                <DxFormLayout>
+                    <DxFormLayoutItem Caption="CustomerName">
+                        @editFormContext.GetEditor(nameof(MassDataReadDto.CustomerName))
+                    </DxFormLayoutItem>
+                    <DxFormLayoutItem Caption="Amount">
+                        @editFormContext.GetEditor(nameof(MassDataReadDto.Amount))
+                    </DxFormLayoutItem>
+                    <DxFormLayoutItem Caption="Category">
+                        @editFormContext.GetEditor(nameof(MassDataReadDto.Category))
+                    </DxFormLayoutItem>
+                    <DxFormLayoutItem Caption="Status">
+                        @editFormContext.GetEditor(nameof(MassDataReadDto.StatusFlag))
+                    </DxFormLayoutItem>
+                </DxFormLayout>
+            </EditFormTemplate>
         </DxGrid>
 
         <div class="pager-container">
@@ -176,10 +163,7 @@ else
 @code {
     private const int PageSize = 100;
     private List<MassDataReadDto> items = new();
-    private MassDataWriteDto formModel = new();
-    private string amountText = string.Empty;
     private bool isLoading;
-    private bool showForm;
     private string? errorMessage;
     private string? infoMessage;
     private int pageIndex;
@@ -219,61 +203,38 @@ else
         await LoadPage(index);
     }
 
-    private void StartCreate()
+    private async Task OnEditModelSaving(GridEditModelSavingEventArgs e)
     {
-        infoMessage = "Anlegen ist aktuell noch nicht verfügbar.";
+        errorMessage = null;
-    }
+        infoMessage = null;
 
-    private void StartEdit(MassDataReadDto item)
+        var editModel = (MassDataReadDto)e.EditModel;
-    {
+        var dto = new MassDataWriteDto
-        formModel = new MassDataWriteDto
         {
-            CustomerName = item.CustomerName,
+            CustomerName = editModel.CustomerName,
-            Amount = item.Amount,
+            Amount = editModel.Amount,
-            Category = item.Category,
+            Category = editModel.Category,
-            StatusFlag = item.StatusFlag
+            StatusFlag = editModel.StatusFlag
         };
-        amountText = item.Amount.ToString("0.00");
-        showForm = true;
-        infoMessage = null;
-        errorMessage = null;
-    }
-
-    private async Task HandleSubmit()
-    {
-        errorMessage = null;
-        infoMessage = null;
-
-        if (!decimal.TryParse(amountText, out var amount))
-        {
-            errorMessage = "Amount ist ungültig.";
-            return;
-        }
-
-        formModel.Amount = amount;
 
         try
         {
-            await Api.UpsertAsync(formModel);
+            await Api.UpsertAsync(dto);
             infoMessage = "MassData aktualisiert.";
-            showForm = false;
             await LoadPage(pageIndex);
         }
         catch (Exception ex)
         {
             errorMessage = $"Fehler beim Speichern: {ex.Message}";
+            e.Cancel = true;
         }
     }
 
-    private void CancelEdit()
+    private Task OnDataItemDeleting(GridDataItemDeletingEventArgs e)
     {
-        showForm = false;
-        infoMessage = null;
         errorMessage = null;
-    }
-
-    private void ShowDeleteNotReady()
-    {
         infoMessage = "Löschen ist aktuell noch nicht verfügbar.";
+        e.Cancel = true;
+        return Task.CompletedTask;
     }
 }