public override void DisposingViewModel(uFrame.MVVM.ViewModels.ViewModel viewModel)
 {
     base.DisposingViewModel(viewModel);
     SubScreenViewModelManager.Remove(viewModel);
 }
 public virtual void InitializeSubScreen(SubScreenViewModel viewModel)
 {
     // This is called when a SubScreenViewModel is created
     viewModel.Close.Action = this.CloseHandler;
     SubScreenViewModelManager.Add(viewModel);
 }