使用 raddatagrid 的 itemssource 属性时，在设计时出现参数计数不匹配异常

Question

我有一个在 Windows 10 中运行的 UWP 项目。在我的 mainpage.xml 中，我有一个 RadDataGrid，我将它绑定到我的视图模型上的一个集合，这在运行时可以正常工作。但是在设计时，我遇到了一个异常，阻止我使用设计器。如果我从 raddatagrid 中删除 ItemsSource，设计器会完美运行，所以我想这与此有关，但我不确定是什么。

非常感谢

XAML sn-ps：

<Page x:Class="UWP.MainPage"    
      xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"    
      xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"    
      xmlns:local="using:UWP"
      xmlns:common="using:DataObjects"    
      xmlns:tgrid="using:Telerik.UI.Xaml.Controls.Grid"   
      xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
      xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"  
      mc:Ignorable="d">

<tgrid:RadDataGrid x:Name="DataGrid" 
                   ItemsSource="{x:Bind Path=ViewModel.Tasks}"
                   Grid.Row="1" Grid.Column="0">                      
</tgrid:RadDataGrid>

型号sn-p：

public ObservableRangeCollection<DataObjects.Task> Tasks { get; }  

堆栈跟踪：

TargetParameterCountException: Parameter count mismatch.

 at System.Reflection.RuntimeMethodInfo.InvokeArgumentsCheck(Object obj, BindingFlags invokeAttr, Binder binder, Object[] parameters, CultureInfo culture)
   at System.Reflection.RuntimeMethodInfo.Invoke(Object obj, BindingFlags invokeAttr, Binder binder, Object[] parameters, CultureInfo culture)
   at System.Reflection.RuntimePropertyInfo.GetValue(Object obj, BindingFlags invokeAttr, Binder binder, Object[] index, CultureInfo culture)
   at System.Reflection.RuntimePropertyInfo.GetValue(Object obj, Object[] index)
   at Telerik.Data.Core.BindingExpressionHelper.<>c__DisplayClass0_0.<CreateGetValueFunc>b__0(Object item)
   at Telerik.Data.Core.Fields.PropertyInfoFieldInfo.GetValue(Object item)
   at Telerik.UI.Xaml.Controls.Grid.DataGridTypedColumn.GetValueForInstance(Object instance)
   at Telerik.UI.Xaml.Controls.Grid.Model.GridModel.Telerik.UI.Xaml.Controls.Grid.ITable.GetCellValue(ItemInfo rowItemInfo, ItemInfo columnItemInfo)
   at Telerik.UI.Xaml.Controls.Grid.CellsController`1.GetCellDecorator(IItemInfoNode parentRow, ItemInfo columnItemInfo, Int32 rowLine, Int32 columnLine)
   at Telerik.UI.Xaml.Controls.Grid.CellsController`1.GenerateCellsForRow(IItemInfoNode rowDecorator, Int32 rowSlot)
   at Telerik.UI.Xaml.Controls.Grid.Model.GridModel.GenerateCellsForReadOnlyRow(Int32 rowSlot, Double largestRowElementWidth, IItemInfoNode rowDecorator)
   at Telerik.UI.Xaml.Controls.Grid.Model.GridModel.Telerik.UI.Xaml.Controls.Grid.ITable.GenerateCellsForRow(Int32 rowSlot, Double largestRowElementHeight, IItemInfoNode rowDecorator)
   at Telerik.UI.Xaml.Controls.Grid.NodePool`2.GenerateCellsForLine(Int32 slot, Double largestLength, T lastElement)
   at Telerik.UI.Xaml.Controls.Grid.NodePool`2.GenerateContainer(IList`1 itemInfos)
   at Telerik.UI.Xaml.Controls.Grid.NodePool`2.MeasureForward(MeasureContext& context)
   at Telerik.UI.Xaml.Controls.Grid.NodePool`2.MeasureVertically(RadSize availableSize, Double offset, Double bufferScale)
   at Telerik.UI.Xaml.Controls.Grid.NodePool`2.OnMeasure(RadSize availableSize, Double offset, Int32 frozenElementsCount, Double verticalBufferScale)
   at Telerik.UI.Xaml.Controls.Grid.Model.GridModel.MeasureCells(RadSize newAvailableSize)
   at Telerik.UI.Xaml.Controls.Grid.RadDataGrid.OnCellsPanelMeasure(RadSize newAvailableSize)
   at Telerik.UI.Xaml.Controls.Grid.Primitives.DataGridCellsPanel.MeasureOverride(Size availableSize)
   at Windows.UI.Xaml.UIElement.Measure(Size availableSize)
   at Telerik.UI.Xaml.Controls.Grid.Primitives.DataGridRootPanel.MeasureOverride(Size availableSize)
   at Windows.UI.Xaml.FrameworkElement.MeasureOverride(Size availableSize)
   at Telerik.UI.Xaml.Controls.RadControl.MeasureOverride(Size availableSize)
   at Windows.UI.Xaml.UIElement.UpdateLayout()

Answer 1

如果有什么东西会破坏你的 UI，你可以使用这样的东西：

private static bool? _isInDesignMode;

/// <summary>
/// Gets a value indicating whether the control is in design mode (running in Blend
/// or Visual Studio).
/// </summary>
public static bool IsInDesignModeStatic
{
    get
    {
        if (!_isInDesignMode.HasValue)
        {
#if SILVERLIGHT
            _isInDesignMode = DesignerProperties.IsInDesignTool;
#else
            var prop = DesignerProperties.IsInDesignModeProperty;
            _isInDesignMode
                = (bool)DependencyPropertyDescriptor
                .FromProperty(prop, typeof(FrameworkElement))
                .Metadata.DefaultValue;
#endif
        }

        return _isInDesignMode.Value;
    }
}

此属性将保护您的代码，并且不会在设计模式下执行。 您也可以使用 MVVM 库，例如 MVVMLight 或其他东西。