public AddWindowVM(AddWindow w, MainVM vm)
 {
     Mvm        = vm;
     window     = w;
     AddCommand = new AddCommand(this);
     Db         = new StudentDb();
 }
 public AddWindowCommand(MainVM vm)
 {
     viewModel = vm;
 }
 public SortCommand(MainVM vm)
 {
     viewModel = vm;
 }
 public DeleteCommand(MainVM vm)
 {
     viewModel = vm;
 }
 public AddWindow(MainVM vm)
 {
     InitializeComponent();
     DataContext = new AddWindowVM(this, vm);
 }
 public MainWindow()
 {
     InitializeComponent();
     DataContext = new MainVM(this);
 }