如何在windows 8中停止计时器

我的应用程序中的计时器正在进行一些更改，当更改对我来说足够时，我希望它停止。当它执行stop()方法时，它不会停止。

timerpartAnimation = new DispatcherTimer();
timerpartAnimation.Interval = TimeSpan.FromMilliseconds(1);
timerpartAnimation.Tick += timer_Tick_Anime;
timerpartAnimation.Start();
public void timer_Tick_Anime(object sender, object e)
    {
        newL-=3;
        newT = A * newL + B;
        playPart33.Margin = new Thickness(newL, newT, playPart33.Margin.Right, playPart33.Margin.Bottom);
        if (dis(playPart33.Margin, currentIm.Margin))
        {
            timerpartAnimation.Stop();
            currentIm.Visibility = Windows.UI.Xaml.Visibility.Visible;
        }
    }

奇怪的是这条线：

currentIm.Visibility = Windows.UI.Xaml.Visibility.Visible;

确实发生了，所以它被谨慎地进入if范围。

有人有主意吗？

   public static void ticking(bool tick)
   {
    if(tick)
    {
    timerpartAnimation.Interval = TimeSpan.FromMilliseconds(1);
    }
    else
    {
    timerpartAnimation.Interval = TimeSpan.FromMilliseconds(0);
    }
   }