在Windows Phone 8中对角滑动图像

Question

我正试图在Windows Phone 8 C＃中对角滑动图像，我尝试了一些代码，并且摆脱了我创建的错误 - 但是当我双击画布时，它应该触发事件，但没有发生。请看一下我的代码：

        private void Canvas_DoubleTap(object sender, System.Windows.Input.GestureEventArgs e)
    {
        //The canvas was doubletapped

        //Create DoubleAnimation for x value
        DoubleAnimation movedefenderxpositionAnimation = new DoubleAnimation();
        movedefenderxpositionAnimation.From = 0;
        movedefenderxpositionAnimation.To = 30;
        movedefenderxpositionAnimation.Duration = new Duration(TimeSpan.FromSeconds(1));
        movedefenderxpositionAnimation.AutoReverse = false;

        //Create DoubleAnimation for y value
        DoubleAnimation movedefenderypositionAnimation = new DoubleAnimation();
        movedefenderypositionAnimation.From = 0;
        movedefenderypositionAnimation.To = 15;
        movedefenderypositionAnimation.Duration = new Duration(TimeSpan.FromSeconds(1));
        movedefenderypositionAnimation.AutoReverse = false;

        //Create StoryBoard
        Storyboard movedefenderxpositionSB = new Storyboard();
        movedefenderxpositionSB.Children.Add(movedefenderxpositionAnimation);

        Storyboard movedefenderypositionSB = new Storyboard();
        movedefenderypositionSB.Children.Add(movedefenderypositionAnimation);

        //Set the timespan
        movedefenderxpositionSB.Duration = new Duration(TimeSpan.FromSeconds(1));
        movedefenderypositionSB.Duration = new Duration(TimeSpan.FromSeconds(1));

        //Set the target
        Storyboard.SetTarget(movedefenderxpositionAnimation, squaddefender1);
        Storyboard.SetTarget(movedefenderypositionAnimation, squaddefender1);

        //Set the target property
        Storyboard.SetTargetProperty(movedefenderxpositionAnimation, new PropertyPath("(Canvas.Left)"));
        Storyboard.SetTargetProperty(movedefenderypositionAnimation, new PropertyPath("(Canvas.Top)"));

        //Start the animation
        movedefenderxpositionSB.Begin();
        movedefenderypositionSB.Begin();
    }

而且，我不明白的事情。我怎样才能设置StoryBoard的目标属性，而不是我创建的目标属性两次？我添加了这段代码来解决错误，从而创建了一个新错误