NullReferenceException is thrown when you click a non-frozen cell to start the row edit and RadDataGrid has frozen columns. To reproduce this, the UserEditMode should be set to Inline and at least one of the frozen columns should be read-only (CanUserEdit = False).
The stacktrace of the exception is:
Telerik.WinUI.Controls.dll!Telerik.UI.Xaml.Controls.Grid.XamlGridEditCellGenerator.GenerateContainerForItem(Telerik.UI.Xaml.Controls.Grid.CellGenerationContext info, object containerType) Telerik.WinUI.Controls.dll!Telerik.UI.Xaml.Controls.Grid.CellEditorModelGenerator.GenerateContainerForItem(Telerik.UI.Xaml.Controls.Grid.CellGenerationContext context, object containerType) Telerik.WinUI.Controls.dll!Telerik.UI.Xaml.Controls.Grid.ItemModelGenerator<Telerik.UI.Xaml.Controls.Grid.GridCellEditorModel, Telerik.UI.Xaml.Controls.Grid.CellGenerationContext>.GenerateContainer(Telerik.UI.Xaml.Controls.Grid.CellGenerationContext context) Telerik.WinUI.Controls.dll!Telerik.UI.Xaml.Controls.Grid.CellsController<Telerik.UI.Xaml.Controls.Grid.GridCellEditorModel>.GetCellDecorator(Telerik.UI.Xaml.Controls.Grid.IItemInfoNode parentRow, Telerik.Data.Core.Layouts.ItemInfo columnItemInfo, int rowLine, int columnLine)
Telerik.WinUI.Controls.dll!Telerik.UI.Xaml.Controls.Grid.CellsController<Telerik.UI.Xaml.Controls.Grid.GridCellEditorModel>.GenerateCellsForRow(Telerik.UI.Xaml.Controls.Grid.IItemInfoNode rowDecorator, int rowSlot)
Telerik.WinUI.Controls.dll!Telerik.UI.Xaml.Controls.Grid.Model.GridModel.GenerateCellsForEditRow(int rowSlot, double largestRowElementWidth, Telerik.UI.Xaml.Controls.Grid.IItemInfoNode rowDecorator) Telerik.WinUI.Controls.dll!Telerik.UI.Xaml.Controls.Grid.Model.GridModel.Telerik.UI.Xaml.Controls.Grid.ITable.GenerateCellsForRow(int rowSlot, double largestRowElementHeight, Telerik.UI.Xaml.Controls.Grid.IItemInfoNode rowDecorator) Telerik.WinUI.Controls.dll!Telerik.UI.Xaml.Controls.Grid.EditRowPool.UpdateEditRow(Telerik.Data.Core.Layouts.ItemInfo info, Windows.Foundation.Point startPosition, bool hasFrozenColumns)
Telerik.WinUI.Controls.dll!Telerik.UI.Xaml.Controls.Grid.Model.GridModel.UpdateEditRow() Telerik.WinUI.Controls.dll!Telerik.UI.Xaml.Controls.Grid.Model.GridModel.ArrangeCells(Windows.Foundation.Size finalSize) Telerik.WinUI.Controls.dll!Telerik.UI.Xaml.Controls.Grid.RadDataGrid.OnCellsPanelArrange(Windows.Foundation.Size finalSize) Telerik.WinUI.Controls.dll!Telerik.UI.Xaml.Controls.Grid.Primitives.DataGridCellsPanel.ArrangeOverride(Windows.Foundation.Size finalSize)
The frozen group rows area overlaps part of the column headers on horizontal scroll. This happens when GroupHeaderDisplayMode is Frozen.
To work this around, set the GroupHeaderDisplayMode to Scrollable.
<telerikGrid:RadDataGrid GroupHeaderDisplayMode="Scrollable">
A group can get duplicated when the GroupHeaderDisplayMode is Frozen (this is the default mode). In this case, a group visual is drawn in both the frozen headers area and the scrollable area below.
To work this around, set the GroupHeaderDisplayMode property to Scrollable.
<telerikGrid:RadDataGrid x:Name="dataGrid" GroupHeaderDisplayMode="Scrollable">
The MessageResultEventArgs' DataObjectResult property is empty when the ReportMessageResult event is raised for the SelectedItems property. The SelectedItems property is reported when the event is raised for a ListMessage with multiple selection enabled.
To work this around, instead of the DataObjectResult property, use the SelectedItems of the ListView control which presents the items in the ListMessage.
private void RadChat_ReportMessageResult(object sender, MessageResultEventArgs e)
{
if (e.Message is ListMessage lm && e.PropertyName == nameof(ListView.SelectedItems))
{
var listView = this.chat.ChildrenOfType<ListView>().FirstOrDefault(x => x.DataContext == e.Message);
if (listView != null)
{
IList<object> selection = listView.SelectedItems;
}
}
}
The Telerik UI for WinUI Desktop Examples installation fails when using the .appinstaller downloaded from here: https://demos.telerik.com/winui/
Scrolling with the mouse wheel scrolls directly to the bottom of the messages instead of scrolling smoothly between the items.
To work this around, create a custom class that derives from RadChat and override its OnPointerWheelChanged method.
public class CustomChat : RadChat
{
private ScrollViewer scrollViewer;
internal ScrollViewer ScrollViewer
{
get
{
if (this.scrollViewer == null)
{
this.scrollViewer = this.ChildrenOfType<ScrollViewer>().Where(sc => sc.Name == "PART_ScrollViewer").FirstOrDefault();
}
return this.scrollViewer;
}
}
protected override void OnPointerWheelChanged(PointerRoutedEventArgs e)
{
if (this.ScrollViewer != null)
{
int delta = e.GetCurrentPoint(this).Properties.MouseWheelDelta;
double wheelDetents = delta / 120.0;
double scrollableRange = ScrollViewer.ExtentHeight - ScrollViewer.ViewportHeight;
double step = 0.01 * scrollableRange;
double offsetDelta = wheelDetents * step;
double newOffset = ScrollViewer.VerticalOffset - offsetDelta;
newOffset = Math.Max(0, Math.Min(ScrollViewer.ExtentHeight, newOffset));
ScrollViewer.ScrollToVerticalOffset(newOffset);
}
}
}
The click actions (like cell selection and sorting) stop working when RadDataGrid is hosted in a RadTabControl or TabView. To reproduce this, you should select the tab item with the data grid, then select another tab, and select back the tab with the data grid. This prevents the hit testing in the RadDataGrid element.
The issue occurs because the hit test service used in the RadDataGrid implementation. The hit test service relies on the IsLoaded property of RadDataGrid (inherited from RadControl). The property is set in the Loaded and Unloaded events. However, when switching tabs, the Unloaded event is invoked on deselection, but on second selection of the same tab, the Loaded event is never called again, thus IsLoaded is false.
To work this around, you can subscribe to the PreviewSelectionChanged event of RadTabControl and manually update the internal isLoaded field of the data grid.
private void RadTabControl_PreviewSelectionChanged(object sender, Telerik.UI.Xaml.Controls.RadSelectionChangedEventArgs e)
{
if (e.AddedItems.Count > 0)
{
var gridView = ((RadTabItem)e.AddedItems[0]).Content as RadDataGrid;
var isLoadedField = typeof(RadControl).GetField("isLoaded", System.Reflection.BindingFlags.Instance | System.Reflection.BindingFlags.NonPublic);
isLoadedField.SetValue(gridView, true);
}
}
Hello,
when I create a ContentDialog (or Popup) containing a RadDataGrid, row/cell selection doesn't work. It seems like all pointer events are ignored on the cells panel. Here is the sample code:
using Microsoft.UI.Xaml;
using Microsoft.UI.Xaml.Controls;
using Telerik.UI.Xaml.Controls.Grid;
namespace GridTest
{
/// <summary>
/// An empty window that can be used on its own or navigated to within a Frame.
/// </summary>
public sealed partial class MainWindow : Window
{
public MainWindow()
{
InitializeComponent();
}
private void Button_Click(object sender, RoutedEventArgs e)
{
ContentDialog contentDialog = new ContentDialog()
{
Content = new RadDataGrid()
{
ItemsSource = new DummyData[] { new DummyData("Item 1") }
}
};
contentDialog.XamlRoot = this.Content.XamlRoot;
contentDialog.ShowAsync();
}
}
public record DummyData(string Text);
}
Could you please fix this as soon as possible or provide me a workaround for this bug
Greetings
Heiko