contrôle DataGrid personnalisé avec ControlTemplate et ContentPresenter

Question

J'ai une coutume DataGrid (j'ai étendu et inclus un DependencyPropertyLabel), je me sers du DataGrid et voulait ajouter Label contrôle à l'aide ControlTemplate et ContentPresenter. Dans le ContentTemplate le DependencyPropertyLabel fonctionne et affiche comme il se doit, mais le ContentPresenter ne fonctionne pas ou n'affiche aucun contrôle DataGrid. Je l'ai essayé avec ItemsPresenter et il montre les lignes, je me demandais s'il y a un moyen d'afficher le DataGrid en utilisant ContentPresenter de cette manière? Quelle est la bonne approche pour le faire?

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

Le ControlTemplate définit l'apparence du contrôle toute . Vous ne pouvez donc pas simplement mettre un <ContentPresenter /> dans votre modèle et attendre un DataGrid pour apparaître. En outre, vous ne pouvez pas hériter d'une partie seulement d'un ControlTemplate:

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

Vous pouvez copier l'intégralité du modèle par défaut et ajoutez votre Label à ce que:

<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>