我有以下一段 XAML 代码:
<controlsInputToolkit:ContextMenuService.ContextMenu>
<controlsInputToolkit:ContextMenu
Height="75"
Width="200"
IsOpen="False"
Visibility="Collapsed"
Closed="mnuPopup_Closed"
x:Name="mnuPopup">
<controlsInputToolkit:MenuItem
x:Name="mnuAnswer911Call"
Header="Answer Call"
Click="mnuAnswer911Call_Click"
IsEnabled="True"/>
<controlsInputToolkit:MenuItem
x:Name="mnuHangup911Call"
Header="Hangup call"
Click="mnuHangup911Call_Click"
IsEnabled="True"/>
</controlsInputToolkit:ContextMenu>
</controlsInputToolkit:ContextMenuService.ContextMenu>
假设,根据上下文,我想向mnuAnswer911Call
菜单项添加一个子菜单。我该怎么办?