我可以 bind/set 类型类型的依赖项 属性 到 DataTemplate 的 DataType

Question

我正在创建自定义用户控件。我的目标是使控件可重用。 我正在使用 ItemsControl，这里是 XAML

<ItemsControl ItemsSource="{Binding Path=ItemSource , RelativeSource={RelativeSource FindAncestor, AncestorType={x:Type controls:MyItemsControlWithButtons}}}">
                <ItemsControl.ItemTemplate>
                    <DataTemplate DataType="{x:Type Type=typeOf(DataTemplateType)????}">
                        <ContentControl x:Name="instruction" Content="{Binding Path=DataTemplateControl, RelativeSource={RelativeSource FindAncestor, AncestorType={x:Type controls:MyItemsControlWithButtons}}}"/>
                        <DataTemplate.Triggers>
                            <Trigger Property="ItemsControl.AlternationIndex" Value="0">
                                <Setter Property="Background" Value="#DDDDDD" TargetName="instruction" />
                            </Trigger>
                            <Trigger Property="ItemsControl.AlternationIndex" Value="1">
                                <Setter Property="Background" Value="#EEEEEE" TargetName="instruction" />
                            </Trigger>
                        </DataTemplate.Triggers>
                    </DataTemplate>
              </ItemsControl.ItemTemplate>
</ItemsControl>

这里是control:MyItemsControlWithButtons

public partial class DraggableItemsControlWithButtons : UserControl
    {
        public DraggableItemsControlWithButtons()
        {
            InitializeComponent();
        }

        public static readonly DependencyProperty DataTemplateTypeProperty =
        DependencyProperty.Register(nameof(DataTemplateType), typeof(Type), typeof(DraggableItemsControlWithButtons), new UIPropertyMetadata(null));
        public Type DataTemplateType
        {
            get { return (Type)GetValue(DataTemplateTypeProperty); }
            set { SetValue(DataTemplateTypeProperty, value); }
        }

        public static readonly DependencyProperty ItemSourceProperty =
        DependencyProperty.Register(nameof(ItemSource), typeof(IEnumerable), typeof(DraggableItemsControlWithButtons), new UIPropertyMetadata(null));
        public IEnumerable ItemSource
        {
            get { return (IEnumerable)GetValue(ItemSourceProperty); }
            set { SetValue(ItemSourceProperty, value); }
        }

        public static readonly DependencyProperty DataTemplateControlProperty =
        DependencyProperty.Register(nameof(DataTemplateControl), typeof(Control), typeof(DraggableItemsControlWithButtons), new UIPropertyMetadata(null));
        public Control DataTemplateControl
        {
            get { return (Control)GetValue(DataTemplateControlProperty); }
            set { SetValue(DataTemplateControlProperty, value); }
        }
    }

如您所见，我想将 bind/set DataTemplateType 转换为 ItemsControl.ItemTemplate 的 DataTemplate

的 DataType

如何实现？

谢谢

Answer 1

您可以通过将 DataTemplateControl 属性 替换为 ItemTemplate 属性 来简化您的控制。并完成与 ItemsControl 的相似性，将 ItemSource 属性 重命名为 ItemsSource.

public static readonly DependencyProperty ItemsSourceProperty =
    DependencyProperty.Register(
        nameof(ItemsSource), typeof(IEnumerable),
        typeof(DraggableItemsControlWithButtons));

public IEnumerable ItemsSource
{
    get { return (IEnumerable)GetValue(ItemsSourceProperty); }
    set { SetValue(ItemsSourceProperty, value); }
}

public static readonly DependencyProperty ItemTemplateProperty =
    DependencyProperty.Register(
        nameof(ItemTemplate), typeof(DataTemplate),
        typeof(DraggableItemsControlWithButtons));

public DataTemplate ItemTemplate
{
    get { return (DataTemplate)GetValue(ItemSourceProperty); }
    set { SetValue(ItemSourceProperty, value); }
}

UserControl XAML 中的 ItemsControl 如下所示：

<ItemsControl
    ItemsSource="{Binding ItemsSource,
                          RelativeSource={RelativeSource AncestorType=UserControl}}"
    ItemTemplate="{Binding ItemTemplate,
                           RelativeSource={RelativeSource AncestorType=UserControl}}" />

然后，您可以像在任何其他带有 ItemTemplate 属性:

的控件中一样分配 ItemTemplate

<local:DraggableItemsControlWithButtons ItemSource="{Binding ...}">
    <local:DraggableItemsControlWithButtons.ItemTemplate>
        <DataTemplate>
           ...
        </DataTemplate>
    </local:DraggableItemsControlWithButtons.ItemTemplate>
</local:DraggableItemsControlWithButtons>