與控件模板和ContentPresenter

Question

自定義DataGrid控件我有一個自定義DataGrid（我擴展，幷包括了DependencyPropertyLabel），我使用的是DataGrid並希望增加使用ControlTemplate和ContentPresenterLabel控制。在ContentTemplate中，DependencyPropertyLabel按原樣工作並顯示，但ContentPresenter根本無法工作或顯示任何DataGrid控件。我試了ItemsPresenter它顯示的行，我想知道是否有一種方法來顯示使用ContentPresenter這樣DataGrid？做這件事的正確方法是什麼？

MyUserControl.xaml

<UserControl 
    x:Class="MyNamespace.UI.MyUserControl" 
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" 
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" 
    xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" 
    xmlns:d="http://schemas.microsoft.com/expression/blend/2008" 
    xmlns:e="clr-namespace:MyNamespace.UI" 
    mc:Ignorable="d" 
    d:DesignHeight="350" d:DesignWidth="400"> 
    <UserControl.Resources> 
     <Style TargetType="{x:Type e:DataGrid}" BasedOn="{StaticResource {x:Type DataGrid}}"> 
      <Setter Property="Template"> 
       <Setter.Value> 
        <ControlTemplate TargetType="{x:Type e:DataGrid}"> 
         <StackPanel> 
          <Label Content="{Binding Label, RelativeSource={RelativeSource TemplatedParent}}" ContentStringFormat="{}{0}: " /> 
          <ContentPresenter Margin="2" HorizontalAlignment="Center" VerticalAlignment="Center"/> 
         </StackPanel> 
        </ControlTemplate> 
       </Setter.Value> 
      </Setter> 
     </Style> 
    </UserControl.Resources> 
    <WrapPanel x:Name="LayoutRoot" Width="900" HorizontalAlignment="Stretch" Margin="12" VerticalAlignment="Stretch"> 
     <e:DataGrid Label="My Label 1"  ItemsSource="{Binding Source={StaticResource MySource1}}"/> 
     <e:DataGrid Label="My Label 2"  ItemsSource="{Binding Source={StaticResource MySource2}}"/> 
    </WrapPanel> 
</UserControl> 

DataGrid.cs

namespace MyNamespace.UI 
{ 
    public class DataGrid : System.Windows.Controls.DataGrid 
    { 
     public string Label 
     { 
      get { return (string)GetValue(LabelProperty); } 
      set { SetValue(LabelProperty, value); } 
     } 

     public static readonly DependencyProperty LabelProperty = 
      DependencyProperty.Register("Label", typeof(string), typeof(DataGrid), new UIPropertyMetadata("")); 

     public DataGrid() 
     {} 
    } 
} 

Answer 1

的ControlTemplate限定整個控件的外觀。因此，您不能簡單地將<ContentPresenter />放入您的模板中，並且預計會顯示DataGrid。此外，您不能繼承ControlTemplate中的一部分：

WPF: Is there a way to override part of a ControlTemplate without redefining the whole style?

你可以複製整個默認模板，並添加Label它雖然：

<Style TargetType="{x:Type e:DataGrid}" BasedOn="{StaticResource {x:Type DataGrid}}"> 
    <Setter Property="Template"> 
     <Setter.Value> 
      <ControlTemplate TargetType="{x:Type DataGrid}"> 
       <Border BorderBrush="{TemplateBinding BorderBrush}" BorderThickness="{TemplateBinding BorderThickness}" Background="{TemplateBinding Background}" Padding="{TemplateBinding Padding}" SnapsToDevicePixels="True"> 
        <ScrollViewer x:Name="DG_ScrollViewer" Focusable="false"> 
         <ScrollViewer.Template> 
          <ControlTemplate TargetType="{x:Type ScrollViewer}"> 
           <Grid> 
            <Grid.ColumnDefinitions> 
             <ColumnDefinition Width="Auto"/> 
             <ColumnDefinition Width="*"/> 
             <ColumnDefinition Width="Auto"/> 
            </Grid.ColumnDefinitions> 
            <Grid.RowDefinitions> 
             <RowDefinition Height="Auto"/> 
             <RowDefinition Height="Auto"/> 
             <RowDefinition Height="*"/> 
             <RowDefinition Height="Auto"/> 
            </Grid.RowDefinitions> 
            <Label Content="{Binding Label, RelativeSource={RelativeSource TemplatedParent}}" ContentStringFormat="{}{0}: " /> 
            <Button Grid.Row="1" Command="{x:Static DataGrid.SelectAllCommand}" Focusable="false" Style="{DynamicResource {ComponentResourceKey ResourceId=DataGridSelectAllButtonStyle, TypeInTargetAssembly={x:Type DataGrid}}}" Visibility="{Binding HeadersVisibility, ConverterParameter={x:Static DataGridHeadersVisibility.All}, Converter={x:Static DataGrid.HeadersVisibilityConverter}, RelativeSource={RelativeSource AncestorType={x:Type DataGrid}}}" Width="{Binding CellsPanelHorizontalOffset, RelativeSource={RelativeSource AncestorType={x:Type DataGrid}}}"/> 
            <DataGridColumnHeadersPresenter x:Name="PART_ColumnHeadersPresenter" Grid.Row="1" Grid.Column="1" Visibility="{Binding HeadersVisibility, ConverterParameter={x:Static DataGridHeadersVisibility.Column}, Converter={x:Static DataGrid.HeadersVisibilityConverter}, RelativeSource={RelativeSource AncestorType={x:Type DataGrid}}}"/> 
            <ScrollContentPresenter x:Name="PART_ScrollContentPresenter" CanContentScroll="{TemplateBinding CanContentScroll}" Grid.ColumnSpan="2" Grid.Row="2"/> 
            <ScrollBar x:Name="PART_VerticalScrollBar" Grid.Column="2" Maximum="{TemplateBinding ScrollableHeight}" Orientation="Vertical" Grid.Row="2" Visibility="{TemplateBinding ComputedVerticalScrollBarVisibility}" Value="{Binding VerticalOffset, Mode=OneWay, RelativeSource={RelativeSource TemplatedParent}}" ViewportSize="{TemplateBinding ViewportHeight}"/> 
            <Grid Grid.Column="1" Grid.Row="3"> 
             <Grid.ColumnDefinitions> 
              <ColumnDefinition Width="{Binding NonFrozenColumnsViewportHorizontalOffset, RelativeSource={RelativeSource AncestorType={x:Type DataGrid}}}"/> 
              <ColumnDefinition Width="*"/> 
             </Grid.ColumnDefinitions> 
             <ScrollBar x:Name="PART_HorizontalScrollBar" Grid.Column="1" Maximum="{TemplateBinding ScrollableWidth}" Orientation="Horizontal" Visibility="{TemplateBinding ComputedHorizontalScrollBarVisibility}" Value="{Binding HorizontalOffset, Mode=OneWay, RelativeSource={RelativeSource TemplatedParent}}" ViewportSize="{TemplateBinding ViewportWidth}"/> 
            </Grid> 
           </Grid> 
          </ControlTemplate> 
         </ScrollViewer.Template> 
         <ItemsPresenter SnapsToDevicePixels="{TemplateBinding SnapsToDevicePixels}"/> 
        </ScrollViewer> 
       </Border> 
      </ControlTemplate> 
     </Setter.Value> 
    </Setter> 
    <Style.Triggers> 
     <MultiTrigger> 
      <MultiTrigger.Conditions> 
       <Condition Property="IsGrouping" Value="true"/> 
       <Condition Property="VirtualizingPanel.IsVirtualizingWhenGrouping" Value="false"/> 
      </MultiTrigger.Conditions> 
      <Setter Property="ScrollViewer.CanContentScroll" Value="false"/> 
     </MultiTrigger> 
    </Style.Triggers> 
</Style>