private void OnFilesListBoxKeyDown(object sender, KeyEventArgs e)
 {
     OpenFileViewModel viewModel = (OpenFileViewModel)DataContext;
     switch (e.Key)
     {
         case Key.Enter:
             viewModel.OpenSelectedFileSystemInfo();
             break;
         case Key.Back:
             viewModel.OpenParentFileSystemInfo();
             break;
     }
 }
 private void OnFilesListBoxItemMouseDoubleClick(object sender, MouseButtonEventArgs e)
 {
     OpenFileViewModel viewModel = (OpenFileViewModel)DataContext;
     viewModel.OpenSelectedFileSystemInfo();
 }