XAML WP8.1 AppBarButton保持事件

我一個下面的XAML：XAML WP8.1 AppBarButton保持事件

<Page.BottomAppBar> 
     <CommandBar> 
      <AppBarButton Label="- запись -" Icon="Microphone" Holding="AppBarButton_Holding" PointerPressed="AppBarButton_PointerPressed" PointerReleased="AppBarButton_PointerReleased" /> 
      <AppBarButton Label="обновить" Icon="Refresh" Click="AppBarButton_Click" /> 
      <CommandBar.SecondaryCommands> 
       <AppBarButton Label="выйти" Click="AppBarButton_Click_1"/> 
      </CommandBar.SecondaryCommands> 
     </CommandBar> 
    </Page.BottomAppBar>

，所以我試圖趕上Holding事件（或以某種方式瞭解該按鈕被竊聽然後被釋放）在AppBarButton：

private void AppBarButton_Holding(object sender, HoldingRoutedEventArgs e) 
     { 
      string holdingState = (e.HoldingState == Windows.UI.Input.HoldingState.Started) ? "Holding" : "Held"; 
      Debug.WriteLine(holdingState); 
     } 

     private void AppBarButton_PointerPressed(object sender, PointerRoutedEventArgs e) 
     { 
      Debug.WriteLine("pressed!"); 
     } 

     private void AppBarButton_PointerReleased(object sender, PointerRoutedEventArgs e) 
     { 
      Debug.WriteLine("released!"); 
     }

但我不進入這些處理程序，這是奇怪，我的任何 ...

這個文檔是歸仁等奇怪： https://msdn.microsoft.com/library/windows/apps/windows.ui.xaml.controls.appbarbutton.aspx