Silverlight实现跑马灯动画

<Grid x:Name="Layout" Background="White">
  <Canvas x:Name="canvas" Background="Black" Grid.Row="1" Height="280">
    <!--隐藏矩形以外的其它部分-->
    <Canvas.Clip >
     <RectangleGeometry x:Name="rg" />
    </Canvas.Clip>
  <StackPanel x:Name="sp" Orientation="Horizontal" ></StackPanel>
  </Canvas>
 <Image x:Name="img_Full" Width="640" Height="480" Visibility="Collapsed" MouseLeftButtonUp="img_Full_MouseLeftButtonUp" />
</Grid>

 public partial class Demo : UserControl
  {
    //定义
    private Storyboard storyboard;
    private const double photowidth = 320;
    private double totalwidth;
    public Demo()
    {
      InitializeComponent();
      CreatePhoto();
    }
    /// <summary>
    /// 创建图片列表
    /// </summary>
    private void CreatePhoto()
    {
      string[] picList = new string[] { "1.jpg", "2.jpg", "3.jpg", "4.jpg", "5.jpg" };
      //创建多组图片，保证图片不会出现空白,因为StackPanel是横向排列的，这样就可以把图片类似模拟的排成一圈
      for (int i = 0; i < 3; i++)
      {
        //根据数组创建图片
        for (int j = 0; j < picList.Length; j++)
        {
          UC_pic pic = new UC_pic();
          pic.ImageUrl = "../images/photo/" + picList[j];
          pic.Width = photowidth;
          //绑定事件
          pic.MouseEnter += new MouseEventHandler(pic_MouseEnter);
          pic.MouseLeave += new MouseEventHandler(pic_MouseLeave);
          pic.MouseLeftButtonUp += new MouseButtonEventHandler(pic_MouseLeftButtonUp);
          //添加对象到StackPanel中
          sp.Children.Add(pic);
        }
      }
      //计算图片的总宽度
      totalwidth = -1.0 * photowidth * picList.Length;
      Canvas.SetLeft(sp, totalwidth);
      //调用初始化 方法
      CreateStoryboard();
      //播放动画
      storyboard.Begin();
      //重新绘制区域
      Resize();
 
    }
    /// <summary>
    /// 创建故事面板
    /// </summary>
    private void CreateStoryboard()
    {
      //创建故事面板
      storyboard = new Storyboard();
      DoubleAnimation animation = new DoubleAnimation();
      //设置动画延时
      animation.Duration = new Duration(TimeSpan.FromSeconds(2.0));
      //设置对象的作用属性
      Storyboard.SetTarget(animation, sp);
      Storyboard.SetTargetProperty(animation, new PropertyPath("(Canvas.Left)", new object[0]));
      //添加到动画故事板内
      storyboard.Children.Add(animation);
      //动画自动完成事件
      storyboard.Completed += new EventHandler(storyboard_Completed);
    }
 
    //动画自动完成事件，当动画播放完成（结束）的时候。再次循环动画
    void storyboard_Completed(object sender, EventArgs e)
    {
      DoubleAnimation animation = (DoubleAnimation)storyboard.Children[0];
      //取得图片当前位置
      double left = Canvas.GetLeft(sp);
      //如果图片已接近最后，就重新设置位置
      if (left > (totalwidth - photowidth))
      {
        animation.From = new double?(left);
      }
      //设置动画的起始值（From）所依据的总量（总长度）
      animation.By = new double?(totalwidth);
      //循环动画
      storyboard.Begin();
    }
    private void Resize()
    {
      //重新绘制显示区域
      rg.Rect = new Rect(0, 0, this.ActualWidth, 260);
    }
 
    void pic_MouseLeftButtonUp(object sender, MouseButtonEventArgs e)
    {
      //显示放大图片
      UC_pic pic = sender as UC_pic;
      img_Full.Source = pic.photo.Source;
      img_Full.Visibility = Visibility.Visible;
    }
 
    void pic_MouseLeave(object sender, MouseEventArgs e)
    {
      //继续动画
      storyboard.Resume();
    }
 
    void pic_MouseEnter(object sender, MouseEventArgs e)
    {
      //暂停动画
      storyboard.Pause();
    }
 
    private void img_Full_MouseLeftButtonUp(object sender, MouseButtonEventArgs e)
    {
      //隐藏放大图片
      img_Full.Visibility = Visibility.Collapsed;
    }
 
    private void UserControl_SizeChanged(object sender, SizeChangedEventArgs e)
    {
      //动画根据屏幕大小改变而改变
      Resize();
    }
}

<Canvas x:Name="LayoutRoot" Background="White">
  <Image x:Name="photo" Width="320" Height="240" Stretch="UniformToFill" Margin="10" />
</Canvas>

public partial class UC_pic : UserControl
  {
    public UC_pic()
    {
      InitializeComponent();
    }
    private string _imgUrl;
    public string ImageUrl
    {
      get { return this._imgUrl; }
      set { 
        //设置图片资源属性
        this._imgUrl = value;
        Uri uri = new Uri(value, UriKind.Relative);
        BitmapImage bitimg = new BitmapImage(uri);
        this.photo.Source = bitimg;
      }
    }
  }