How to reference right-clicked object in WPF Context Menu item click event handler?

note the CommandParameter

<Grid Background="Red" Height="100" Width="100">
    <Grid.ContextMenu>
        <ContextMenu>
            <MenuItem 
                Header="Change status" 
                Click="EditStatusCm_Click"
                CommandParameter="{Binding RelativeSource={RelativeSource Self}, Path=Parent}" />
        </ContextMenu>
    </Grid.ContextMenu>
</Grid>

and use it in the handler to figure out which Grid it is

    private void EditStatusCm_Click(object sender, RoutedEventArgs e)
    {
        MenuItem mi = sender as MenuItem;
        if (mi != null)
        {
            ContextMenu cm = mi.CommandParameter as ContextMenu;
            if (cm != null)
            {
                Grid g = cm.PlacementTarget as Grid;
                if (g != null)
                {
                    Console.WriteLine(g.Background); // Will print red
                }
            }
        }
    }

Update:
If you want the menuitem handler to get to the Grid's children instead of the Grid itself, use this approach

<Grid Background="Red" Height="100" Width="100">
    <Grid.Resources>
        <ContextMenu x:Key="TextBlockContextMenu">
            <MenuItem 
                Header="Change status" 
                Click="EditStatusCm_Click"
                CommandParameter="{Binding RelativeSource={RelativeSource Self}, Path=Parent}" />
        </ContextMenu>

        <Style TargetType="{x:Type TextBlock}">
            <Setter Property="ContextMenu" Value="{StaticResource TextBlockContextMenu}" />
        </Style>
    </Grid.Resources>

    <Grid.RowDefinitions>
        <RowDefinition />
        <RowDefinition />
    </Grid.RowDefinitions>

    <TextBlock Text="Row0" Grid.Row="0" />
    <TextBlock Text="Row1" Grid.Row="1" />
</Grid>

Just replace the TextBlocks with whatever your custom object type is. Then in the event handler, replace Grid g = cm.PlacementTarget as Grid with TextBlock t = cm.PlacementTarget as TextBlock (or whatever your custom object type is).

By binding the Data Context like so in the xaml:

ContextMenu DataContext="{Binding PlacementTarget.DataContext, RelativeSource=    {RelativeSource Self}}">

You can then do this:

private void Context_MenuClick(object sender, RoutedEventArgs e)
{
   var menuItem = e.Source as MenuItem;

   MyDoStuffFunction(menuItem.DataContext);
}

The data context will be bound to the object that was clicked to open the ContextMenu.

I got it from a codeproject article at this link:

http://www.codeproject.com/Articles/162784/WPF-ContextMenu-Strikes-Again-DataContext-Not-Upda

menu = sender as MenuItem will be null if the sender is not a MenuItem or a derived class thereof. Subsequently trying to dereference menu will blow up.

It's likely that your sender is a Menu or ContextMenu or a ToolStripMenuItem or some other form of menu item, rather than specifically being a MenuItem object. Use a debugger breakpoint to stop the code here and examine the sender object to see exactly what class it is.