将ICommand绑定到父ViewModel

Question

I have two user controls LeftPanel and DeviceList . DeviceList is inside the LeftPanel . I want the context menu in device list to be able to call a command on the parent view model, which is set on a grid that hosts DeviceList . I have tried the following but it does not work.

Here is the ContextMenu within DeviceList

<MenuItem Command="{Binding RelativeSource={RelativeSource Mode=FindAncestor,
                    AncestorType={x:Type local:LeftPanel}},
                    Path=DeviceListViewModel.RemoveDevice}">

Here is the LeftPanel usercontrol

<UserControl x:Class="Tool.LeftPanel" .... >
    <Grid DataContext="{Binding DeviceListViewModel}" Grid.Column="1">
        <local:DeviceList Grid.Row="1" Margin="0,0,0,10"/>

Answer 1

I had a similar problem, but the ContextMenu does not see the DataContext of the ViewModel or the Parent. A possible solution is here Access ViewModel / DataConext inside ContextMenu .

Answer 2

the contextmenu is not part of the visualtree, so i think your binding is simply wrong because the datacontext is not what you think of.

use Snoop to check your DataContext and bindings at runtime

i assume that you have to work with PlacementTarget in your bindings