/// <summary>
/// Returns the currently visible ViewModel
/// </summary>
public static INavigatableViewModel GetCurrentViewModel(this NavigationState This)
{
return(This.NavigationStack.LastOrDefault());
}
/// <summary>
/// Locate the first ViewModel in the stack that matches a certain Type.
/// </summary>
/// <returns>The matching ViewModel or null if none exists.</returns>
public static T FindViewModelInStack <T>(this NavigationState This)
where T : INavigatableViewModel
{
return(This.NavigationStack.Reverse().OfType <T>().FirstOrDefault());
}