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;      }    }  }