WPF binding Ancestor object as CommandParameter
I have a Custom usercontrol that I want to enlarge. I tested this whit a function call on  MouseDoubleClick and it worked fine. 
Code:

    XAML
    <cc:UserControl ItemsSource="{Binding Path=DataItem}" MouseDoubleClick="UserControl_MouseDoubleClick" />
    
    CodeBehind c#
    private void UserControl_MouseDoubleClick(object sender, MouseButtonEventArgs e)
    {
    	MainWindowViewModel.Instance.LightBoxCommand.Execute(sender);
    }

Now i want to do it with MVVM pattern and in a menu like this:

    XAML
    <cc:UserControl ItemsSource="{Binding Path=DataItem}" MouseDoubleClick="UserControl_MouseDoubleClick" >
    	<cc:UserControl.ContextMenu>
    		<ContextMenu>
    			<MenuItem Header="_Enlarge"
    					  Command="{Binding Path=EnlargeCommand, RelativeSource={RelativeSource AncestorType={x:Type cc:UserControl}}}" CommandParameter="{Binding Path=.}"
    					   />
    			</MenuItem>
    		</ContextMenu>
    	</cc:UserControl.ContextMenu>
    </cc:UserControl>
    
    MVVM C#
    private ICommand _enlargeCommand;
    public ICommand EnlargeCommand
    {
    	get
    	{
    		if (_enlargeCommand == null)
    			_enlargeCommand = new RelayCommand(n => {MainWindowViewModel.Instance.LightBoxCommand.Execute(n); });
    		return _enlargeCommand;
    	}
    }

The problem is that I'm not quite sure how to bind to the parent object, i want to send the whole UserControl to the "LightBoxCommand". Any ideas? 
WPF binding Ancestor object as CommandParameter
===

I have a Custom usercontrol that I want to enlarge. I tested this whit a function call on  MouseDoubleClick and it worked fine. 
Code:

    XAML
    <cc:UserControl ItemsSource="{Binding Path=DataItem}" MouseDoubleClick="UserControl_MouseDoubleClick" />
    
    CodeBehind c#
    private void UserControl_MouseDoubleClick(object sender, MouseButtonEventArgs e)
    {
    	MainWindowViewModel.Instance.LightBoxCommand.Execute(sender);
    }

Now i want to do it with MVVM pattern and in a menu like this:

    XAML
    <cc:UserControl ItemsSource="{Binding Path=DataItem}" MouseDoubleClick="UserControl_MouseDoubleClick" >
    	<cc:UserControl.ContextMenu>
    		<ContextMenu>
    			<MenuItem Header="_Enlarge"
    					  Command="{Binding Path=EnlargeCommand, RelativeSource={RelativeSource AncestorType={x:Type cc:UserControl}}}" CommandParameter="{Binding Path=.}"
    					   />
    			</MenuItem>
    		</ContextMenu>
    	</cc:UserControl.ContextMenu>
    </cc:UserControl>
    
    MVVM C#
    private ICommand _enlargeCommand;
    public ICommand EnlargeCommand
    {
    	get
    	{
    		if (_enlargeCommand == null)
    			_enlargeCommand = new RelayCommand(n => {MainWindowViewModel.Instance.LightBoxCommand.Execute(n); });
    		return _enlargeCommand;
    	}
    }

The problem is that I'm not quite sure how to bind to the parent object, i want to send the whole UserControl to the "LightBoxCommand". Any ideas? 