How do you bind a command to a MenuItem (WPF)?

Question

Here is my code from the View.xaml.cs:

private RelayCommand _closeCommand;
public ICommand CloseCommand
{
    get
    {
        if (_closeCommand == null)
        {
            _closeCommand = new RelayCommand(param => this.OnClose());
        }
        return _closeCommand;
    }
}

public void OnClose()
{
    Close();
}

And here is some code from my View.xaml:

<Window.ContextMenu>
    <ContextMenu>
        <MenuItem Name="menuItem_Close" Header="Close" Command="{Binding CloseCommand}" />
    </ContextMenu> 
</Window.ContextMenu>

When I run the program and select the close menu item, nothing happens. The CloseCommand code doesn't even get executed.

Solution

ContextMenu is not part of the VisualTree, that's why the DataContext will not be inherited. Here ContextMenu.PlacementTarget is some kind of relay to get the Window:

<MenuItem Name="menuItem_Close" Header="Close"
          Command="{Binding Path=PlacementTarget.DataContext.CloseCommand, RelativeSource={RelativeSource AncestorType=ContextMenu}}" />

Comments

[McGarnagle]

Are you sure it doesn't get the DataContext? In my test it seems to be inheriting the DataContext as you would expect ...

[Jackson Dean Goodwin]

I tried your code for the Command="..." but it did not work - just as before - nothing happed.

[LPL]

@dbaseman According to this Popup creates its own visualtree. This means no DataContext inheritance for ContextMenu which is placed in a Popup.

[LPL]

@JacksonDeanGoodwin Any binding errors? Are you sure that DataContext is set for Window? Maybe try a Button with your Command binding in Window directly for that.

[Agent007]

Thanks for this. How should I bind a static ICommand to a MenuItem not using a ViewModel binding? I am currently using (which is not working) Command="{x:Static ...}" but that doesn't seem to work with the solution you have provided here. Please help.