Refactor grid and band layout persistence logic

Unify band and grid layout saving into a single "Layout speichern" action and method. Store the full grid layout in BandLayout, and simplify column/band rendering logic. Apply saved layouts after render for consistency. Remove obsolete ordering logic and update messages for clarity. These changes improve robustness and maintainability of layout persistence in CatalogsGrid and MassDataGrid.

DbFirst.BlazorWasm/Components/CatalogsGrid.razor

@@ -2,6 +2,7 @@
 @using Microsoft.AspNetCore.Components
 @using Microsoft.AspNetCore.Components.Rendering
 @using Microsoft.AspNetCore.Components.Forms
+@using DevExpress.Blazor
 @inject CatalogApiClient Api
 @inject LayoutApiClient LayoutApi
 @inject IJSRuntime JsRuntime
@@ -96,8 +97,7 @@ else
     <div class="band-editor">
         <div class="band-controls">
             <DxButton Text="Band hinzufügen" Click="AddBand" />
-            <DxButton Text="Band-Layout speichern" Click="SaveBandLayoutAsync" Enabled="@CanSaveBandLayout" />
+            <DxButton Text="Layout speichern" Click="SaveLayoutAsync" Enabled="@CanSaveBandLayout" />
-            <DxButton Text="Grid-Layout speichern" Click="SaveGridLayoutAsync" Enabled="@CanSaveBandLayout" />
             <DxButton Text="Band-Layout zurücksetzen" Click="ResetBandLayoutAsync" />
         </div>
         @foreach (var band in bandLayout.Bands)
@@ -211,6 +211,8 @@ else
 
     private bool CanSaveBandLayout => !string.IsNullOrWhiteSpace(layoutUser);
 
+    private bool gridLayoutApplied;
+
     protected override async Task OnInitializedAsync()
     {
         columnLookup = columnDefinitions.ToDictionary(column => column.FieldName, StringComparer.OrdinalIgnoreCase);
@@ -219,6 +221,16 @@ else
         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 void SetEditContext(EditContext context)
     {
         if (editContext == context)
@@ -457,16 +469,10 @@ else
 
         columnBandAssignments = BuildAssignmentsFromLayout(bandLayout);
         ApplyColumnLayoutFromStorage();
-        ApplyBandOrderingFromColumnOrder();
         UpdateBandOptions();
     }
 
-    private async Task SaveBandLayoutAsync()
+    private async Task SaveLayoutAsync()
-    {
-        await SaveGridLayoutAsync();
-    }
-
-    private async Task SaveGridLayoutAsync()
     {
         if (string.IsNullOrWhiteSpace(layoutUser))
         {
@@ -485,15 +491,39 @@ else
                 UserName = layoutUser,
                 LayoutData = layoutData
             });
-            infoMessage = "Grid-Layout gespeichert.";
+            infoMessage = "Layout gespeichert.";
             errorMessage = null;
         }
         catch (Exception ex)
         {
-            errorMessage = $"Grid-Layout konnte nicht gespeichert werden: {ex.Message}";
+            errorMessage = $"Layout konnte nicht gespeichert werden: {ex.Message}";
         }
     }
 
+    private void CaptureColumnLayoutFromGrid()
+    {
+        if (gridRef == null)
+        {
+            return;
+        }
+
+        var layout = gridRef.SaveLayout();
+        bandLayout.GridLayout = layout;
+
+        var orderedColumns = layout.Columns
+            .Where(column => !string.IsNullOrWhiteSpace(column.FieldName))
+            .OrderBy(column => column.VisibleIndex)
+            .ToList();
+
+        bandLayout.ColumnOrder = orderedColumns
+            .Select(column => column.FieldName)
+            .ToList();
+
+        bandLayout.ColumnWidths = orderedColumns
+            .Where(column => !string.IsNullOrWhiteSpace(column.Width))
+            .ToDictionary(column => column.FieldName, column => column.Width, StringComparer.OrdinalIgnoreCase);
+    }
+
     private async Task ResetBandLayoutAsync()
     {
         if (string.IsNullOrWhiteSpace(layoutUser))
@@ -510,17 +540,6 @@ else
 
     private void ApplyColumnLayoutFromStorage()
     {
-        if (bandLayout.ColumnOrder.Count > 0)
-        {
-            var ordered = bandLayout.ColumnOrder
-                .Where(columnLookup.ContainsKey)
-                .Select(field => columnLookup[field])
-                .ToList();
-
-            ordered.AddRange(columnDefinitions.Where(column => !ordered.Contains(column)));
-            columnDefinitions = ordered;
-        }
-
         foreach (var column in columnDefinitions)
         {
             if (bandLayout.ColumnWidths.TryGetValue(column.FieldName, out var width) && !string.IsNullOrWhiteSpace(width))
@@ -532,30 +551,6 @@ else
         columnLookup = columnDefinitions.ToDictionary(column => column.FieldName, StringComparer.OrdinalIgnoreCase);
     }
 
-    private void CaptureColumnLayoutFromGrid()
-    {
-        if (gridRef == null)
-        {
-            return;
-        }
-
-        var gridColumns = gridRef.GetColumns()
-            .OfType<IGridDataColumn>()
-            .Where(column => !string.IsNullOrWhiteSpace(column.FieldName))
-            .ToList();
-
-        bandLayout.ColumnOrder = gridColumns
-            .OrderBy(column => column.VisibleIndex)
-            .Select(column => column.FieldName)
-            .ToList();
-
-        bandLayout.ColumnWidths = gridColumns
-            .Where(column => !string.IsNullOrWhiteSpace(column.Width))
-            .ToDictionary(column => column.FieldName, column => column.Width, StringComparer.OrdinalIgnoreCase);
-
-        ApplyBandOrderingFromColumnOrder();
-    }
-
     private void ApplyBandOrderingFromColumnOrder()
     {
         if (bandLayout.ColumnOrder.Count == 0)
@@ -671,6 +666,8 @@ else
     {
         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))
@@ -710,88 +707,15 @@ else
         builder.AddAttribute(seq++, "Width", "120px");
         builder.CloseComponent();
 
-        var bandLookup = bandLayout.Bands.ToDictionary(band => band.Id, StringComparer.OrdinalIgnoreCase);
+        var grouped = bandLayout.Bands.SelectMany(band => band.Columns).ToHashSet(StringComparer.OrdinalIgnoreCase);
-        var renderedBands = new HashSet<string>(StringComparer.OrdinalIgnoreCase);
+        foreach (var column in columnDefinitions.Where(column => !grouped.Contains(column.FieldName)))
-        var orderedFields = bandLayout.ColumnOrder
-            .Where(columnLookup.ContainsKey)
-            .ToList();
-
-        if (orderedFields.Count == 0)
         {
-            var grouped = bandLayout.Bands.SelectMany(band => band.Columns).ToHashSet(StringComparer.OrdinalIgnoreCase);
+            BuildDataColumn(builder, ref seq, column);
-            foreach (var column in columnDefinitions.Where(column => !grouped.Contains(column.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();
-            }
-
-            return;
-        }
-
-        foreach (var fieldName in orderedFields)
-        {
-            if (columnBandAssignments.TryGetValue(fieldName, out var bandId) && bandLookup.TryGetValue(bandId, out var band))
-            {
-                if (!renderedBands.Add(bandId) || 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();
-            }
-            else if (columnLookup.TryGetValue(fieldName, out var column))
-            {
-                BuildDataColumn(builder, ref seq, column);
-            }
-        }
-
-        foreach (var column in columnDefinitions)
-        {
-            if (!orderedFields.Contains(column.FieldName, StringComparer.OrdinalIgnoreCase) &&
-                (!columnBandAssignments.TryGetValue(column.FieldName, out var bandId) || !bandLookup.ContainsKey(bandId)))
-            {
-                BuildDataColumn(builder, ref seq, column);
-            }
         }
 
         foreach (var band in bandLayout.Bands)
         {
-            if (renderedBands.Contains(band.Id) || band.Columns.Count == 0)
+            if (band.Columns.Count == 0)
             {
                 continue;
             }
@@ -856,6 +780,7 @@ else
         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; }
     }
 
     private sealed class BandDefinition

DbFirst.BlazorWasm/Components/MassDataGrid.razor

@@ -2,6 +2,7 @@
 @using Microsoft.AspNetCore.Components
 @using Microsoft.AspNetCore.Components.Rendering
 @using Microsoft.AspNetCore.Components.Forms
+@using DevExpress.Blazor
 @inject MassDataApiClient Api
 @inject LayoutApiClient LayoutApi
 @inject IJSRuntime JsRuntime
@@ -131,8 +132,7 @@ else
     <div class="band-editor">
         <div class="band-controls">
             <DxButton Text="Band hinzufügen" Click="AddBand" />
-            <DxButton Text="Band-Layout speichern" Click="SaveBandLayoutAsync" Enabled="@CanSaveBandLayout" />
+            <DxButton Text="Layout speichern" Click="SaveLayoutAsync" Enabled="@CanSaveBandLayout" />
-            <DxButton Text="Grid-Layout speichern" Click="SaveGridLayoutAsync" Enabled="@CanSaveBandLayout" />
             <DxButton Text="Band-Layout zurücksetzen" Click="ResetBandLayoutAsync" />
         </div>
         @foreach (var band in bandLayout.Bands)
@@ -353,16 +353,10 @@ else
 
         columnBandAssignments = BuildAssignmentsFromLayout(bandLayout);
         ApplyColumnLayoutFromStorage();
-        ApplyBandOrderingFromColumnOrder();
         UpdateBandOptions();
     }
 
-    private async Task SaveBandLayoutAsync()
+    private async Task SaveLayoutAsync()
-    {
-        await SaveGridLayoutAsync();
-    }
-
-    private async Task SaveGridLayoutAsync()
     {
         if (string.IsNullOrWhiteSpace(layoutUser))
         {
@@ -381,15 +375,39 @@ else
                 UserName = layoutUser,
                 LayoutData = layoutData
             });
-            infoMessage = "Grid-Layout gespeichert.";
+            infoMessage = "Layout gespeichert.";
             errorMessage = null;
         }
         catch (Exception ex)
         {
-            errorMessage = $"Grid-Layout konnte nicht gespeichert werden: {ex.Message}";
+            errorMessage = $"Layout konnte nicht gespeichert werden: {ex.Message}";
         }
     }
 
+    private void CaptureColumnLayoutFromGrid()
+    {
+        if (gridRef == null)
+        {
+            return;
+        }
+
+        var layout = gridRef.SaveLayout();
+        bandLayout.GridLayout = layout;
+
+        var orderedColumns = layout.Columns
+            .Where(column => !string.IsNullOrWhiteSpace(column.FieldName))
+            .OrderBy(column => column.VisibleIndex)
+            .ToList();
+
+        bandLayout.ColumnOrder = orderedColumns
+            .Select(column => column.FieldName)
+            .ToList();
+
+        bandLayout.ColumnWidths = orderedColumns
+            .Where(column => !string.IsNullOrWhiteSpace(column.Width))
+            .ToDictionary(column => column.FieldName, column => column.Width, StringComparer.OrdinalIgnoreCase);
+    }
+
     private async Task ResetBandLayoutAsync()
     {
         if (string.IsNullOrWhiteSpace(layoutUser))
@@ -406,17 +424,6 @@ else
 
     private void ApplyColumnLayoutFromStorage()
     {
-        if (bandLayout.ColumnOrder.Count > 0)
-        {
-            var ordered = bandLayout.ColumnOrder
-                .Where(columnLookup.ContainsKey)
-                .Select(field => columnLookup[field])
-                .ToList();
-
-            ordered.AddRange(columnDefinitions.Where(column => !ordered.Contains(column)));
-            columnDefinitions = ordered;
-        }
-
         foreach (var column in columnDefinitions)
         {
             if (bandLayout.ColumnWidths.TryGetValue(column.FieldName, out var width) && !string.IsNullOrWhiteSpace(width))
@@ -428,73 +435,6 @@ else
         columnLookup = columnDefinitions.ToDictionary(column => column.FieldName, StringComparer.OrdinalIgnoreCase);
     }
 
-    private void CaptureColumnLayoutFromGrid()
-    {
-        if (gridRef == null)
-        {
-            return;
-        }
-
-        var gridColumns = gridRef.GetColumns()
-            .OfType<IGridDataColumn>()
-            .Where(column => !string.IsNullOrWhiteSpace(column.FieldName))
-            .ToList();
-
-        bandLayout.ColumnOrder = gridColumns
-            .OrderBy(column => column.VisibleIndex)
-            .Select(column => column.FieldName)
-            .ToList();
-
-        bandLayout.ColumnWidths = gridColumns
-            .Where(column => !string.IsNullOrWhiteSpace(column.Width))
-            .ToDictionary(column => column.FieldName, column => column.Width, StringComparer.OrdinalIgnoreCase);
-
-        ApplyBandOrderingFromColumnOrder();
-    }
-
-    private void ApplyBandOrderingFromColumnOrder()
-    {
-        if (bandLayout.ColumnOrder.Count == 0)
-        {
-            return;
-        }
-
-        var bandById = bandLayout.Bands.ToDictionary(band => band.Id, StringComparer.OrdinalIgnoreCase);
-        var orderedBandIds = new List<string>();
-        var orderedColumnsByBand = bandLayout.Bands.ToDictionary(
-            band => band.Id,
-            _ => new List<string>(),
-            StringComparer.OrdinalIgnoreCase);
-
-        foreach (var field in bandLayout.ColumnOrder)
-        {
-            if (columnBandAssignments.TryGetValue(field, out var bandId) && bandById.ContainsKey(bandId))
-            {
-                if (!orderedBandIds.Contains(bandId, StringComparer.OrdinalIgnoreCase))
-                {
-                    orderedBandIds.Add(bandId);
-                }
-
-                orderedColumnsByBand[bandId].Add(field);
-            }
-        }
-
-        foreach (var band in bandLayout.Bands)
-        {
-            var orderedColumns = orderedColumnsByBand[band.Id];
-            orderedColumns.AddRange(band.Columns.Where(column => !orderedColumns.Contains(column, StringComparer.OrdinalIgnoreCase)));
-            band.Columns = orderedColumns;
-        }
-
-        if (orderedBandIds.Count > 0)
-        {
-            bandLayout.Bands = orderedBandIds
-                .Select(id => bandById[id])
-                .Concat(bandLayout.Bands.Where(band => !orderedBandIds.Contains(band.Id, StringComparer.OrdinalIgnoreCase)))
-                .ToList();
-        }
-    }
-
     private void AddBand()
     {
         bandLayout.Bands.Add(new BandDefinition
@@ -581,6 +521,8 @@ else
     {
         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))
@@ -606,88 +548,15 @@ else
         builder.AddAttribute(seq++, "Width", "120px");
         builder.CloseComponent();
 
-        var bandLookup = bandLayout.Bands.ToDictionary(band => band.Id, StringComparer.OrdinalIgnoreCase);
+        var grouped = bandLayout.Bands.SelectMany(band => band.Columns).ToHashSet(StringComparer.OrdinalIgnoreCase);
-        var renderedBands = new HashSet<string>(StringComparer.OrdinalIgnoreCase);
+        foreach (var column in columnDefinitions.Where(column => !grouped.Contains(column.FieldName)))
-        var orderedFields = bandLayout.ColumnOrder
-            .Where(columnLookup.ContainsKey)
-            .ToList();
-
-        if (orderedFields.Count == 0)
         {
-            var grouped = bandLayout.Bands.SelectMany(band => band.Columns).ToHashSet(StringComparer.OrdinalIgnoreCase);
+            BuildDataColumn(builder, ref seq, column);
-            foreach (var column in columnDefinitions.Where(column => !grouped.Contains(column.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();
-            }
-
-            return;
-        }
-
-        foreach (var fieldName in orderedFields)
-        {
-            if (columnBandAssignments.TryGetValue(fieldName, out var bandId) && bandLookup.TryGetValue(bandId, out var band))
-            {
-                if (!renderedBands.Add(bandId) || 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();
-            }
-            else if (columnLookup.TryGetValue(fieldName, out var column))
-            {
-                BuildDataColumn(builder, ref seq, column);
-            }
-        }
-
-        foreach (var column in columnDefinitions)
-        {
-            if (!orderedFields.Contains(column.FieldName, StringComparer.OrdinalIgnoreCase) &&
-                (!columnBandAssignments.TryGetValue(column.FieldName, out var bandId) || !bandLookup.ContainsKey(bandId)))
-            {
-                BuildDataColumn(builder, ref seq, column);
-            }
         }
 
         foreach (var band in bandLayout.Bands)
         {
-            if (renderedBands.Contains(band.Id) || band.Columns.Count == 0)
+            if (band.Columns.Count == 0)
             {
                 continue;
             }
@@ -873,6 +742,7 @@ else
         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; }
     }
 
     private sealed class BandDefinition
@@ -934,4 +804,16 @@ else
         public int? Value { get; set; }
         public string Text { get; set; } = string.Empty;
     }
+
+    private bool gridLayoutApplied;
+
+    protected override async Task OnAfterRenderAsync(bool firstRender)
+    {
+        if (!gridLayoutApplied && gridRef != null && bandLayout.GridLayout != null)
+        {
+            gridRef.LoadLayout(bandLayout.GridLayout);
+            gridLayoutApplied = true;
+            await InvokeAsync(StateHasChanged);
+        }
+    }
 }

DbFirst.BlazorWebApp/Components/CatalogsGrid.razor

@@ -2,6 +2,7 @@
 @using Microsoft.AspNetCore.Components
 @using Microsoft.AspNetCore.Components.Rendering
 @using Microsoft.AspNetCore.Components.Forms
+@using DevExpress.Blazor
 @inject CatalogApiClient Api
 @inject LayoutApiClient LayoutApi
 @inject IJSRuntime JsRuntime
@@ -55,8 +56,7 @@ else
     <div class="band-editor">
         <div class="band-controls">
             <DxButton Text="Band hinzufügen" Click="AddBand" />
-            <DxButton Text="Band-Layout speichern" Click="SaveBandLayoutAsync" Enabled="@CanSaveBandLayout" />
+            <DxButton Text="Layout speichern" Click="SaveLayoutAsync" Enabled="@CanSaveBandLayout" />
-            <DxButton Text="Grid-Layout speichern" Click="SaveGridLayoutAsync" Enabled="@CanSaveBandLayout" />
             <DxButton Text="Band-Layout zurücksetzen" Click="ResetBandLayoutAsync" />
         </div>
         @foreach (var band in bandLayout.Bands)
@@ -394,12 +394,7 @@ else
         }
     }
 
-    private async Task SaveBandLayoutAsync()
+    private async Task SaveLayoutAsync()
-    {
-        await SaveGridLayoutAsync();
-    }
-
-    private async Task SaveGridLayoutAsync()
     {
         if (string.IsNullOrWhiteSpace(layoutUser))
         {
@@ -418,15 +413,39 @@ else
                 UserName = layoutUser,
                 LayoutData = layoutData
             });
-            infoMessage = "Grid-Layout gespeichert.";
+            infoMessage = "Layout gespeichert.";
             errorMessage = null;
         }
         catch (Exception ex)
         {
-            errorMessage = $"Grid-Layout konnte nicht gespeichert werden: {ex.Message}";
+            errorMessage = $"Layout konnte nicht gespeichert werden: {ex.Message}";
         }
     }
 
+    private void CaptureColumnLayoutFromGrid()
+    {
+        if (gridRef == null)
+        {
+            return;
+        }
+
+        var layout = gridRef.SaveLayout();
+        bandLayout.GridLayout = layout;
+
+        var orderedColumns = layout.Columns
+            .Where(column => !string.IsNullOrWhiteSpace(column.FieldName))
+            .OrderBy(column => column.VisibleIndex)
+            .ToList();
+
+        bandLayout.ColumnOrder = orderedColumns
+            .Select(column => column.FieldName)
+            .ToList();
+
+        bandLayout.ColumnWidths = orderedColumns
+            .Where(column => !string.IsNullOrWhiteSpace(column.Width))
+            .ToDictionary(column => column.FieldName, column => column.Width, StringComparer.OrdinalIgnoreCase);
+    }
+
     private async Task LoadBandLayoutAsync()
     {
         if (string.IsNullOrWhiteSpace(layoutUser))
@@ -449,77 +468,9 @@ else
 
         columnBandAssignments = BuildAssignmentsFromLayout(bandLayout);
         ApplyColumnLayoutFromStorage();
-        ApplyBandOrderingFromColumnOrder();
         UpdateBandOptions();
     }
 
-    private void CaptureColumnLayoutFromGrid()
-    {
-        if (gridRef == null)
-        {
-            return;
-        }
-
-        var gridColumns = gridRef.GetColumns()
-            .OfType<IGridDataColumn>()
-            .Where(column => !string.IsNullOrWhiteSpace(column.FieldName))
-            .ToList();
-
-        bandLayout.ColumnOrder = gridColumns
-            .OrderBy(column => column.VisibleIndex)
-            .Select(column => column.FieldName)
-            .ToList();
-
-        bandLayout.ColumnWidths = gridColumns
-            .Where(column => !string.IsNullOrWhiteSpace(column.Width))
-            .ToDictionary(column => column.FieldName, column => column.Width, StringComparer.OrdinalIgnoreCase);
-
-        ApplyBandOrderingFromColumnOrder();
-    }
-
-    private void ApplyBandOrderingFromColumnOrder()
-    {
-        if (bandLayout.ColumnOrder.Count == 0)
-        {
-            return;
-        }
-
-        var bandById = bandLayout.Bands.ToDictionary(band => band.Id, StringComparer.OrdinalIgnoreCase);
-        var orderedBandIds = new List<string>();
-        var orderedColumnsByBand = bandLayout.Bands.ToDictionary(
-            band => band.Id,
-            _ => new List<string>(),
-            StringComparer.OrdinalIgnoreCase);
-
-        foreach (var field in bandLayout.ColumnOrder)
-        {
-            if (columnBandAssignments.TryGetValue(field, out var bandId) && bandById.ContainsKey(bandId))
-            {
-                if (!orderedBandIds.Contains(bandId, StringComparer.OrdinalIgnoreCase))
-                {
-                    orderedBandIds.Add(bandId);
-                }
-
-                orderedColumnsByBand[bandId].Add(field);
-            }
-        }
-
-        foreach (var band in bandLayout.Bands)
-        {
-            var orderedColumns = orderedColumnsByBand[band.Id];
-            orderedColumns.AddRange(band.Columns.Where(column => !orderedColumns.Contains(column, StringComparer.OrdinalIgnoreCase)));
-            band.Columns = orderedColumns;
-        }
-
-        if (orderedBandIds.Count > 0)
-        {
-            bandLayout.Bands = orderedBandIds
-                .Select(id => bandById[id])
-                .Concat(bandLayout.Bands.Where(band => !orderedBandIds.Contains(band.Id, StringComparer.OrdinalIgnoreCase)))
-                .ToList();
-        }
-    }
-
     private void AddBand()
     {
         bandLayout.Bands.Add(new BandDefinition
@@ -592,6 +543,8 @@ else
     {
         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))
@@ -631,88 +584,15 @@ else
         builder.AddAttribute(seq++, "Width", "120px");
         builder.CloseComponent();
 
-        var bandLookup = bandLayout.Bands.ToDictionary(band => band.Id, StringComparer.OrdinalIgnoreCase);
+        var grouped = bandLayout.Bands.SelectMany(band => band.Columns).ToHashSet(StringComparer.OrdinalIgnoreCase);
-        var renderedBands = new HashSet<string>(StringComparer.OrdinalIgnoreCase);
+        foreach (var column in columnDefinitions.Where(column => !grouped.Contains(column.FieldName)))
-        var orderedFields = bandLayout.ColumnOrder
-            .Where(columnLookup.ContainsKey)
-            .ToList();
-
-        if (orderedFields.Count == 0)
         {
-            var grouped = bandLayout.Bands.SelectMany(band => band.Columns).ToHashSet(StringComparer.OrdinalIgnoreCase);
+            BuildDataColumn(builder, ref seq, column);
-            foreach (var column in columnDefinitions.Where(column => !grouped.Contains(column.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();
-            }
-
-            return;
-        }
-
-        foreach (var fieldName in orderedFields)
-        {
-            if (columnBandAssignments.TryGetValue(fieldName, out var bandId) && bandLookup.TryGetValue(bandId, out var band))
-            {
-                if (!renderedBands.Add(bandId) || 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();
-            }
-            else if (columnLookup.TryGetValue(fieldName, out var column))
-            {
-                BuildDataColumn(builder, ref seq, column);
-            }
-        }
-
-        foreach (var column in columnDefinitions)
-        {
-            if (!orderedFields.Contains(column.FieldName, StringComparer.OrdinalIgnoreCase) &&
-                (!columnBandAssignments.TryGetValue(column.FieldName, out var bandId) || !bandLookup.ContainsKey(bandId)))
-            {
-                BuildDataColumn(builder, ref seq, column);
-            }
         }
 
         foreach (var band in bandLayout.Bands)
         {
-            if (renderedBands.Contains(band.Id) || band.Columns.Count == 0)
+            if (band.Columns.Count == 0)
             {
                 continue;
             }
@@ -762,6 +642,7 @@ else
         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; }
     }
 
     private sealed class BandDefinition
@@ -825,17 +706,6 @@ else
 
     private void ApplyColumnLayoutFromStorage()
     {
-        if (bandLayout.ColumnOrder.Count > 0)
-        {
-            var ordered = bandLayout.ColumnOrder
-                .Where(columnLookup.ContainsKey)
-                .Select(field => columnLookup[field])
-                .ToList();
-
-            ordered.AddRange(columnDefinitions.Where(column => !ordered.Contains(column)));
-            columnDefinitions = ordered;
-        }
-
         foreach (var column in columnDefinitions)
         {
             if (bandLayout.ColumnWidths.TryGetValue(column.FieldName, out var width) && !string.IsNullOrWhiteSpace(width))
@@ -846,4 +716,16 @@ else
 
         columnLookup = columnDefinitions.ToDictionary(column => column.FieldName, StringComparer.OrdinalIgnoreCase);
     }
+
+    private bool gridLayoutApplied;
+
+    protected override async Task OnAfterRenderAsync(bool firstRender)
+    {
+        if (!gridLayoutApplied && gridRef != null && bandLayout.GridLayout != null)
+        {
+            gridRef.LoadLayout(bandLayout.GridLayout);
+            gridLayoutApplied = true;
+            await InvokeAsync(StateHasChanged);
+        }
+    }
 }

DbFirst.BlazorWebApp/Components/MassDataGrid.razor

@@ -2,6 +2,7 @@
 @using Microsoft.AspNetCore.Components
 @using Microsoft.AspNetCore.Components.Rendering
 @using Microsoft.AspNetCore.Components.Forms
+@using DevExpress.Blazor
 @inject MassDataApiClient Api
 @inject LayoutApiClient LayoutApi
 @inject IJSRuntime JsRuntime
@@ -131,8 +132,7 @@ else
     <div class="band-editor">
         <div class="band-controls">
             <DxButton Text="Band hinzufügen" Click="AddBand" />
-            <DxButton Text="Band-Layout speichern" Click="SaveBandLayoutAsync" Enabled="@CanSaveBandLayout" />
+            <DxButton Text="Layout speichern" Click="SaveLayoutAsync" Enabled="@CanSaveBandLayout" />
-            <DxButton Text="Grid-Layout speichern" Click="SaveGridLayoutAsync" Enabled="@CanSaveBandLayout" />
             <DxButton Text="Band-Layout zurücksetzen" Click="ResetBandLayoutAsync" />
         </div>
         @foreach (var band in bandLayout.Bands)
@@ -353,16 +353,11 @@ else
 
         columnBandAssignments = BuildAssignmentsFromLayout(bandLayout);
         ApplyColumnLayoutFromStorage();
-        ApplyBandOrderingFromColumnOrder();
+        //ApplyBandOrderingFromColumnOrder();
         UpdateBandOptions();
     }
 
-    private async Task SaveBandLayoutAsync()
+    private async Task SaveLayoutAsync()
-    {
-        await SaveGridLayoutAsync();
-    }
-
-    private async Task SaveGridLayoutAsync()
     {
         if (string.IsNullOrWhiteSpace(layoutUser))
         {
@@ -381,15 +376,39 @@ else
                 UserName = layoutUser,
                 LayoutData = layoutData
             });
-            infoMessage = "Grid-Layout gespeichert.";
+            infoMessage = "Layout gespeichert.";
             errorMessage = null;
         }
         catch (Exception ex)
         {
-            errorMessage = $"Grid-Layout konnte nicht gespeichert werden: {ex.Message}";
+            errorMessage = $"Layout konnte nicht gespeichert werden: {ex.Message}";
         }
     }
 
+    private void CaptureColumnLayoutFromGrid()
+    {
+        if (gridRef == null)
+        {
+            return;
+        }
+
+        var layout = gridRef.SaveLayout();
+        bandLayout.GridLayout = layout;
+
+        var orderedColumns = layout.Columns
+            .Where(column => !string.IsNullOrWhiteSpace(column.FieldName))
+            .OrderBy(column => column.VisibleIndex)
+            .ToList();
+
+        bandLayout.ColumnOrder = orderedColumns
+            .Select(column => column.FieldName)
+            .ToList();
+
+        bandLayout.ColumnWidths = orderedColumns
+            .Where(column => !string.IsNullOrWhiteSpace(column.Width))
+            .ToDictionary(column => column.FieldName, column => column.Width, StringComparer.OrdinalIgnoreCase);
+    }
+
     private async Task ResetBandLayoutAsync()
     {
         if (string.IsNullOrWhiteSpace(layoutUser))
@@ -404,30 +423,6 @@ else
         infoMessage = "Band-Layout zurückgesetzt.";
     }
 
-    private void CaptureColumnLayoutFromGrid()
-    {
-        if (gridRef == null)
-        {
-            return;
-        }
-
-        var gridColumns = gridRef.GetColumns()
-            .OfType<IGridDataColumn>()
-            .Where(column => !string.IsNullOrWhiteSpace(column.FieldName))
-            .ToList();
-
-        bandLayout.ColumnOrder = gridColumns
-            .OrderBy(column => column.VisibleIndex)
-            .Select(column => column.FieldName)
-            .ToList();
-
-        bandLayout.ColumnWidths = gridColumns
-            .Where(column => !string.IsNullOrWhiteSpace(column.Width))
-            .ToDictionary(column => column.FieldName, column => column.Width, StringComparer.OrdinalIgnoreCase);
-
-        ApplyBandOrderingFromColumnOrder();
-    }
-
     private void ApplyBandOrderingFromColumnOrder()
     {
         if (bandLayout.ColumnOrder.Count == 0)
@@ -473,17 +468,6 @@ else
 
     private void ApplyColumnLayoutFromStorage()
     {
-        if (bandLayout.ColumnOrder.Count > 0)
-        {
-            var ordered = bandLayout.ColumnOrder
-                .Where(columnLookup.ContainsKey)
-                .Select(field => columnLookup[field])
-                .ToList();
-
-            ordered.AddRange(columnDefinitions.Where(column => !ordered.Contains(column)));
-            columnDefinitions = ordered;
-        }
-
         foreach (var column in columnDefinitions)
         {
             if (bandLayout.ColumnWidths.TryGetValue(column.FieldName, out var width) && !string.IsNullOrWhiteSpace(width))
@@ -581,6 +565,8 @@ else
     {
         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))
@@ -606,88 +592,15 @@ else
         builder.AddAttribute(seq++, "Width", "120px");
         builder.CloseComponent();
 
-        var bandLookup = bandLayout.Bands.ToDictionary(band => band.Id, StringComparer.OrdinalIgnoreCase);
+        var grouped = bandLayout.Bands.SelectMany(band => band.Columns).ToHashSet(StringComparer.OrdinalIgnoreCase);
-        var renderedBands = new HashSet<string>(StringComparer.OrdinalIgnoreCase);
+        foreach (var column in columnDefinitions.Where(column => !grouped.Contains(column.FieldName)))
-        var orderedFields = bandLayout.ColumnOrder
-            .Where(columnLookup.ContainsKey)
-            .ToList();
-
-        if (orderedFields.Count == 0)
         {
-            var grouped = bandLayout.Bands.SelectMany(band => band.Columns).ToHashSet(StringComparer.OrdinalIgnoreCase);
+            BuildDataColumn(builder, ref seq, column);
-            foreach (var column in columnDefinitions.Where(column => !grouped.Contains(column.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();
-            }
-
-            return;
-        }
-
-        foreach (var fieldName in orderedFields)
-        {
-            if (columnBandAssignments.TryGetValue(fieldName, out var bandId) && bandLookup.TryGetValue(bandId, out var band))
-            {
-                if (!renderedBands.Add(bandId) || 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();
-            }
-            else if (columnLookup.TryGetValue(fieldName, out var column))
-            {
-                BuildDataColumn(builder, ref seq, column);
-            }
-        }
-
-        foreach (var column in columnDefinitions)
-        {
-            if (!orderedFields.Contains(column.FieldName, StringComparer.OrdinalIgnoreCase) &&
-                (!columnBandAssignments.TryGetValue(column.FieldName, out var bandId) || !bandLookup.ContainsKey(bandId)))
-            {
-                BuildDataColumn(builder, ref seq, column);
-            }
         }
 
         foreach (var band in bandLayout.Bands)
         {
-            if (renderedBands.Contains(band.Id) || band.Columns.Count == 0)
+            if (band.Columns.Count == 0)
             {
                 continue;
             }
@@ -873,6 +786,7 @@ else
         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; }
     }
 
     private sealed class BandDefinition
@@ -934,4 +848,16 @@ else
         public int? Value { get; set; }
         public string Text { get; set; } = string.Empty;
     }
+
+    private bool gridLayoutApplied;
+
+    protected override async Task OnAfterRenderAsync(bool firstRender)
+    {
+        if (!gridLayoutApplied && gridRef != null && bandLayout.GridLayout != null)
+        {
+            gridRef.LoadLayout(bandLayout.GridLayout);
+            gridLayoutApplied = true;
+            await InvokeAsync(StateHasChanged);
+        }
+    }
 }