wpf - DataContext 作为资源内转换器绑定的源

Question

 <Canvas.DataContext>
  <ViewModels:VMSomeControl Model="{Binding RelativeSource={RelativeSource TemplatedParent}}" />
 </Canvas.DataContext>

 <!-- DataContext is not passed into these Instances.
      they also have no knowledge of their TemplatedParent. -->
 <Canvas.Resources>

  <!--  is there a way to use a binding that points to the datacontext within the resources ? -->
  <Converters:SomeConverter x:Key="someConverter" 
                            SomeProperty="{Binding Path=Model.SomeProperty}" />

  <!--  is there a way to point Directly to the TemplatedParent  ? -->
  <Converters:SomeConverter x:Key="someConverter" 
                            SomeProperty="{TemplateBinding SomeProperty}" />

 </Canvas.Resources>


 <SomeFrameworkElement SomeProperty="{Binding Path=Model.SomeOtherProperty, Converter={StaticResource someConverter}, ConverterParameter=0}" />

 <SomeFrameworkElement SomeProperty="{Binding Path=Model.SomeOtherProperty, Converter={StaticResource someConverter}, ConverterParameter=1}" />

</Canvas>

是否可以在 ControlTemplate 的根视觉资源中使用使用 dataContext 或 TemplatedParent 的绑定？

Answer 1

以前的答案真的很接近。但多重绑定内的绑定应该是：

<SomeFrameworkElement>
    <SomeFrameworkElement.SomeProperty>
        <MultiBinding Converter="{StaticResource someConverter}" >
            <Binding />
        </MultiBinding>        
    </SomeFrameworkElement.SomeProperty>
</SomeFrameworkElement>

对我有用

Answer 2

如果您希望您的值转换器能够访问数据上下文，您可能需要使用 ConverterParameter：

<SomeFrameworkElement SomeProperty="{Binding Path=Model.SomeOtherProperty, Converter={StaticResource someConverter}, ConverterParameter={Binding DataContext}}" />

然后，数据上下文将作为IValueConverter.Convert实现的参数传递给您的值转换器。

---

如果实现IMultiValueConverter并使用 XAML 中的MultiBinding类绑定参数，则可以将可绑定参数传递给 valueconverter：

<SomeFrameworkElement>
    <SomeFrameworkElement.SomeProperty>
        <MultiBinding Converter="{StaticResource someConverter}" >
            <Binding Path="DataContext"/>
        </MultiBinding>        
    </SomeFrameworkElement.SomeProperty>
</SomeFrameworkElement>

元素的绑定元素作为参数 <MultiBinding>传递给Convert方法。具有以下签名：IMultiValueConvertervaluesConvert

public object Convert(object[] values, Type targetType, object parameter, CultureInfo culture);

Answer 3

SomeProperty="{Binding . ,Converter={StaticResource SomeConverter}, ConverterParameter=someParam}"

点告诉您绑定到 datacontext

Answer 4

Here is a simple and efficient way (that works for my app):

<DataGrid.Columns>
    <DataGridTextColumn Width="*" Header="ColumnHeader">
        <DataGridTextColumn.Binding>
            <Binding Converter="{StaticResource YourConverterKey}" ConverterParameter="DataContext"/>
        </DataGridTextColumn.Binding>
    </DataGridTextColumn>

Now you can use (value) in the Convertor method as your DataContext.