Binding a WPF ShortCut Key to a Command in the ViewModel

The following code can be used to bind a shortcut key directly to a command:

<Window.InputBindings>
    <KeyBinding Command="{Binding Path=NameOfYourCommand}" 
                Key="O" 
                Modifiers="Control"/>
</Window.InputBindings>

Add this after Window.Resources in the XAML code of your view.