DoubleAnimation 创建动画问题

[adonis_net]

步骤1：创建一个Rectangle.
代码:

//初始化bullet
        private void bulletInit(string bulletType)
        {

            rect = new Rectangle();
            var imageBrush = new ImageBrush();
            imageBrush.Stretch = Stretch.None;
            imageBrush.AlignmentX = AlignmentX.Left;
            imageBrush.AlignmentY = AlignmentY.Top;
            switch (bulletType)
            {
                case "green":
                     imageBrush.ImageSource = new BitmapImage(new Uri("/SLADdemo;component/" + bullet[0], UriKind.Relative));
                     break;
                case "ice":
                     imageBrush.ImageSource = new BitmapImage(new Uri("/SLADdemo;component/" + bullet[1], UriKind.Relative));
                     break;
                case "fire":
                     imageBrush.ImageSource = new BitmapImage(new Uri("/SLADdemo;component/" + bullet[2], UriKind.Relative));
                     break;
            }
           
            rect.Fill = imageBrush;
            rect.Width = 47;
            rect.Height = 47;
            LayoutRoot.Children.Add(rect);
            Canvas.SetLeft(rect, 150);
            Canvas.SetTop(rect, 118);
            rect.Visibility = System.Windows.Visibility.Collapsed;
           
        }

步骤2：给矩形创建动画
代码：

//显示
            rect.Visibility = System.Windows.Visibility.Visible;

            //新建动画
            storyboard = new Storyboard();
  

            

            //创建X轴方向动画

            DoubleAnimation da = new DoubleAnimation();


            Duration dur = new Duration(TimeSpan.FromMilliseconds(1000));

            da.Duration = dur;
            da.From = Canvas.GetLeft(rect);
            da.To = 800;

            Storyboard.SetTarget(da, rect);

            Storyboard.SetTargetProperty(da, new PropertyPath("(Canvas.Left)"));

            storyboard.Children.Add(da);

            
            //将动画动态加载进资源内

            if (!Resources.Contains("rectAnimation"))
            {

                Resources.Add("rectAnimation", storyboard);
              

            }

            //动画播放
        
            storyboard.Begin();
            
            
            bulletInit("ice");

问题：动画能正常运行，但是运行过程中图像回时不时往回弹，不是很平滑，请问这是什么原因？

[我说我行就是行]

Storyboard.SetTarget(da, rect);

Storyboard.SetTargetProperty(da, new PropertyPath("(Canvas.Left)"));
你这样设置了，动画可以运行，那你这个rect图像肯定也会随动画而播放啊！