如何使用RelativeSource Binding创建DataGrid绑定到Model和ViewModel？

Question

我有一个具有使用DataGrid的ItemsSource时结合DataGridTemplateColumn一个DataGrid,但在DataGridTemplateColumn的组合框,我希望能够绑定到视图模型的视图,而不是的ItemsSource.

 <DataGrid ItemsSource="{Binding ModelValues, Mode=TwoWay, UpdateSourceTrigger=PropertyChanged}" >
      <DataGridTemplateColumn Header="myHeader" Width="200">
           <DataGridTemplateColumn.CellTemplate>
                <DataTemplate>
                     <ComboBox DisplayMemberPath="Value" SelectedValuePath="Key" IsEnabled="False"
                          SelectedValue="{Binding myID, Mode=TwoWay}"
                          ItemsSource="{Binding Path=myList, 
                          RelativeSource={RelativeSource FindAncestor, AncestorType={x:Type local:ViewModel}}}" />
                </DataTemplate>
           </DataGridTemplateColumn.CellTemplate>
           <DataGridTemplateColumn.CellEditingTemplate>
                <DataTemplate>
                     <ComboBox DisplayMemberPath="Value" SelectedValuePath="Key" IsEnabled="False"
                          SelectedValue="{Binding myID, Mode=TwoWay}"
                          ItemsSource="{Binding Path=myList, 
                          RelativeSource={RelativeSource FindAncestor, AncestorType={x:Type local:ViewModel}}}" />
                </DataTemplate>
           </DataGridTemplateColumn.CellEditingTemplate>
      </DataGridTemplateColumn>
 </DataGrid>

ViewModel有一个ModelValues属性和myList属性.将ModelValues用于ItemsSource的DataGrid,我想用myList的ComboBox ItemsSource.

我如何更改RelativeSource命令以使其有效？

Answer 1

绑定到网格的datacontext:

<DataGrid ItemsSource="{Binding ModelValues, Mode=TwoWay, UpdateSourceTrigger=PropertyChanged}" >
      <DataGridTemplateColumn Header="myHeader" Width="200">
           <DataGridTemplateColumn.CellTemplate>
                <DataTemplate>
                     <ComboBox DisplayMemberPath="Value" SelectedValuePath="Key" IsEnabled="False"
                          SelectedValue="{Binding myID, Mode=TwoWay}"
                          ItemsSource="{Binding Path=DataContext.myList, 
                          RelativeSource={RelativeSource FindAncestor, AncestorType={x:Type DataGrid}}}" />
                </DataTemplate>
           </DataGridTemplateColumn.CellTemplate>
           <DataGridTemplateColumn.CellEditingTemplate>
                <DataTemplate>
                     <ComboBox DisplayMemberPath="Value" SelectedValuePath="Key" IsEnabled="False"
                          SelectedValue="{Binding myID, Mode=TwoWay}"
                          ItemsSource="{Binding Path=DataContext.myList, 
                          RelativeSource={RelativeSource FindAncestor, AncestorType={x:Type DataGrid}}}" />
                </DataTemplate>
           </DataGridTemplateColumn.CellEditingTemplate>
      </DataGridTemplateColumn>
 </DataGrid>