public MainWindowViewModel()
 {
     CategoryTreeViewModel            = new CategoryTreeViewModel();
     DirectoryTreeViewModel           = new DirectoryTreeViewModel();
     IndexMediaFilesViewModel         = new IndexMediaFilesViewModel();
     DirectoryTreeViewModel.OnChange += IndexMediaFilesViewModel.ChangeDirectory;
     CategoryTreeViewModel.OnChange  += IndexMediaFilesViewModel.ChangeCategory;
 }
 public MainWindow()
 {
     InitializeComponent();
     DirectoryTreeViewModel           = new DirectoryTreeViewModel();
     DirectoriesTreeView.DataContext  = DirectoryTreeViewModel;
     IndexMediaFilesViewModel         = new IndexMediaFilesViewModel();
     MediaFilesListBox.DataContext    = IndexMediaFilesViewModel;
     DirectoryTreeViewModel.OnChange += IndexMediaFilesViewModel.ChangeDirectory;
 }