如何获取ContextMenu内部UserControl的原始DataContext。
下面的代码中,您可以看到DataTemplate中有一个Button,它正确地绑定了。然而,在尝试绑定上下文菜单的数据源时,我收到以下错误:
System.Windows.Data Error: 4 : Cannot find source for binding with reference 'RelativeSource FindAncestor, AncestorType='System.Windows.Controls.TreeView', AncestorLevel='1''. BindingExpression:Path=DataContext; DataItem=null; target element is 'ContextMenu' (Name=''); target property is 'DataContext' (type 'Object')
我需要做什么才能允许ContextMenu绑定到ViewModel?
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ViewModel在codebehind中分配给视图的datacontext:
视图:
<TreeView ItemsSource="{Binding Clients}"
cmd:TreeViewSelect.Command="{Binding SelectionChangedCommand}"
cmd:TreeViewSelect.CommandParameter="{Binding RelativeSource={RelativeSource Self},Path=SelectedItem}">
<TreeView.ItemTemplate>
<DataTemplate>
<StackPanel>
<TextBlock Text="{Binding Name}">
<TextBlock.ContextMenu>
<ContextMenu DataContext="{Binding DataContext,
RelativeSource={RelativeSource FindAncestor, AncestorType={x:Type TreeView}}}">
<MenuItem Header="{Binding TestString}" />
</ContextMenu>
</TextBlock.ContextMenu>
</TextBlock>
<Button DataContext="{Binding DataContext,
RelativeSource={RelativeSource FindAncestor, AncestorType={x:Type TreeView}}}"
Content="{Binding TestString}" Command="{Binding EditSelectedClientCommand}" />
</StackPanel>
</DataTemplate>
</TreeView.ItemTemplate>
</TreeView>
ViewModel:
public class ClientListViewModel : ViewModelBase
{
public String TestString {
get {
return "TESTING";
}
}
private ClientList _clients = null;
private readonly IClientService _clientService = null;
private readonly IEventAggregator _eventAggregator = null;
private Client _selectedClient = null;
private ICommand _selectionChangedCommand = null;
private ICommand _editSelectedClientCommand = null;
....
}