Question

我的GridView有RowDetail。我希望每次用户点击行从数据库中获取一些细节时，我都会使用Telerik GridView。以正常方式，这是不可能的，或者至少我不知道如何，因为RowDetail上下文直接绑定到网格DataContext，我想要的不仅仅是GridRow包含它。我发现也许我可以通过命名UserControl将RowDetailTemplate DataContext设置为UserControl，以便我可以将RowDetail引用到其他模型。我的代码是这样的

    <UserControl
    x:Name="mainPageView"
    x:Class="Project.Client.TestView"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
    xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" 
    xmlns:telerik="clr-namespace:Telerik.Windows.Controls;assembly=Telerik.Windows.Controls.GridView" 
    mc:Ignorable="d"
    d:DesignHeight="300" d:DesignWidth="400">

    <UserControl.Resources>
        <DataTemplate x:Key="ContactRowDetailTemplate" >
            <Grid Background="Transparent"
                DataContext="{Binding DataContext.ContactStatModel, 
                ElementName=mainPageView,Mode=OneTime}">
                <Grid.RowDefinitions>
                    <RowDefinition Height="28" />
                </Grid.RowDefinitions>
                <Grid.ColumnDefinitions>
                    <ColumnDefinition Width="Auto" />
                    <ColumnDefinition Width="Auto" />
                    <ColumnDefinition Width="Auto" />
                </Grid.ColumnDefinitions>
                <TextBlock Text="Sent SMS Count" Grid.Column="0" Grid.Row="0" />
                <TextBlock Text=":" Grid.Column="1" Grid.Row="0" />
                <TextBlock Text="{Binding SMSCount}" Grid.Column="2" Grid.Row="0" />

            </Grid>
        </DataTemplate>
    </UserControl.Resources>

    <telerik:RadGridView  
        x:Name="gridView"
        AutoGenerateColumns="False" Height="Auto" Grid.Row="3"
        ItemsSource="{Binding VOutboxList, Mode=TwoWay}"
        SelectedItem="{Binding VOutboxModel, Mode=TwoWay}"
        RowDetailsTemplate="{StaticResource ContactRowDetailTemplate}"
        LoadingRowDetails="gridView_LoadingRowDetails">
        <telerik:RadGridView.Columns>
            <telerik:GridViewDataColumn UniqueName="FirstName"  Header="First Name" Width="150" />
            <telerik:GridViewDataColumn UniqueName="LastName" Header="Last Name" Width="150" />
        </telerik:RadGridView.Columns>
    </telerik:RadGridView>

</UserControl>

但是这次我得到了这个例外

{Error: System.Exception: BindingExpression_CannotFindElementName}

任何建议都会有所帮助。最诚挚的问候。

Answer 1

原因是WPF和Silverlights DataGrid列位于逻辑树之外，因此无法使用使用ElementName指定的绑定源，这在引用ViewModel属性（例如DataGrid模板列中的命令）时很常见。有关此问题的详细信息，请参阅：http://blogs.msdn.com/b/jaimer/archive/2008/11/22/forwarding-the-datagrid-s-datacontext-to-its-columns.aspx

下面的课程就像栏目和周围世界之间的粘合剂一样。它是为Silverlight的内置DataGrid编写的，但应该足够容易使其适应Telerik Grid。它可以像这样使用：

<DataTemplate x:Key="ContactRowDetailTemplate" >
  <Grid Background="Transparent"
    DataContext="{Binding ParentDataGrid.DataContext.ContactStatModel, 
    ElementName=shim,Mode=OneTime}">
        <Shims:DataGridShim x:Name="shim"/>
    <Grid.RowDefinitions>
      <RowDefinition Height="28" />
    </Grid.RowDefinitions>
    <Grid.ColumnDefinitions>
      <ColumnDefinition Width="Auto" />
      <ColumnDefinition Width="Auto" />
      <ColumnDefinition Width="Auto" />
    </Grid.ColumnDefinitions>
    <TextBlock Text="Sent SMS Count" Grid.Column="0" Grid.Row="0" />
    <TextBlock Text=":" Grid.Column="1" Grid.Row="0" />
    <TextBlock Text="{Binding SMSCount}" Grid.Column="2" Grid.Row="0" />
  </Grid>
</DataTemplate>

public class DataGridShim : FrameworkElement
{
  /// <summary>
  /// Initializes a new instance of the <see cref="DataGridShim"/> class.
  /// prepares the ParentDataGrid property for consumption by sibling elements in the DataTemplate
  /// </summary>
  public DataGridShim()
  {
    Loaded += (s, re) =>
    {
      ParentDataGrid = GetContainingDataGrid(this);
    };
  }

  /// <summary>
  /// Gets or sets the parent data grid.
  /// </summary>
  /// <value>
  /// The parent data grid.
  /// </value>
  public DataGrid ParentDataGrid { get; protected set; }

  /// <summary>
  /// Walks the Visual Tree until the DataGrid parent is found and returns it
  /// </summary>
  /// <param name="value">The value.</param>
  /// <returns>The containing datagrid</returns>
  private static DataGrid GetContainingDataGrid(DependencyObject value)
  {
    if (value != null)
    {
      DependencyObject parent = VisualTreeHelper.GetParent(value);
      if (parent != null)
      {
        var grid = parent as DataGrid;
        if (grid != null)
          return grid;

        return GetContainingDataGrid(parent);
      }

      return null;
    }

    return null;
  }
}

Answer 2

我甚至简化了已接受的解决方案。它使用来自DataTemplates的技巧，可以引用静态资源。在静态资源中，您可以在绑定中使用ElementName。

创建一个新控件：

public class ElementProxy : DependencyObject
{
    public DependencyObject Element
    {
        get { return (DependencyObject)GetValue(ElementProperty); }
        set { SetValue(ElementProperty, value); }
    }

public static readonly DependencyProperty ElementProperty =
    DependencyProperty.Register("Element", typeof(DependencyObject), typeof(ElementProxy), new PropertyMetadata(null));
}

将它放入DataGrid或其父控件的静态资源中，并通过StaticResource引用它：

<UserControl.Resources>
    <helpers:ElementProxy Element={Binding ElementName=mainPageView} x:Key="Proxy" />
</UserControl.Resources>

（在列模板中:)

    <DataTemplate>
        <Grid DataContext={Binding Element.DataContext,Source={StaticResource Proxy}} />
    </DataTemplate>

Silverlight数据绑定错误

2 个答案: