前一阵无意中发现将iPod Nano5 横置后会出现一个动态的选歌界面(如下图示),感觉不错于是想用Silverlight来实现一下这个效果,欢迎大家拍砖。

 nano5_thumb_1.jpg

本来是放Demo演示,可是这个程序怎么也显示不出来,只好用图片了(感兴趣的话可以下载源代码):

Capture_thumb.png

 

       在制作过程中比较繁琐的部分是倒影效果,最开始的做法是将同一张专辑图片使用两次:一个作为专辑封面;一个作为倒影效果。对倒影效果图片进行RenderTransform->ScaleY 反转和OpacityMask->LinearGradientBrush 渐变处理,这样操作后出现一个问题:未选中专辑的封面和倒影之间有间隙(如下图示)。这是由于分别对封面和倒影进行PlaneProjection->RotationY 三维旋转时会使它们按各自的坐标轴进行旋转,不是以一个整体进行旋转而差生了偏差。如果将两个图片组合为一个StackPanel 或Canvas 然后再进行旋转感觉应该可以(但需要不少代码实现,效率可能会降低,感兴趣的朋友可以测试一下),最后偷懒用PS 给图片做了倒影~

 pro_thumb.png

 

下面先来看看XAML,这部分就是为Canvas 增加一些事件:

<Canvas x:Name="LayoutRoot" MouseLeftButtonDown="LayoutRoot_MouseLeftButtonDown">  </Canvas>

 

C# 内容请看注释详解:

public partial class MainPage : UserControl  {      private String[] ALBUMS = { "images/ep1.png", "images/ep2.png", "images/ep3.png",                                   "images/ep4.png", "images/ep5.png", "images/ep6.png",                                   "images/ep7.png", "images/ep8.png", "images/ep9.png" };      //当前位置      private double CURRENT = 0;      //目标位置      private double TARGET = 0;      //存储图片      private List<Image> IMAGE = new List<Image>();      //计时器      private DispatcherTimer TIMER = new DispatcherTimer();        public MainPage()      {         InitializeComponent();         //加载图片         addImages();         //对于不同浏览器加载滚轮事件         HtmlPage.Window.AttachEvent("DOMMouseScroll", LayoutRoot_MouseWheel);         HtmlPage.Window.AttachEvent("onmousewheel", LayoutRoot_MouseWheel);         HtmlPage.Document.AttachEvent("onmousewheel", LayoutRoot_MouseWheel);      }        private void addImages()      {          for (int i = 0; i < ALBUMS.Length; i++)          {             //逐一加载图片             string url = ALBUMS[i];             Image cover = new Image();             cover.Source = new BitmapImage(new Uri(url, UriKind.Relative));             LayoutRoot.Children.Add(cover);             //调整图片显示方式             setImage(cover, i);             //将图片加入IMAGE,用于实现动态效果             IMAGE.Add(cover);          }      }        private void setImage(Image image, int index)      {          //遍历图片与当前(CURRENT)位置关系          double offset = index - CURRENT;          //对图片进行三维旋转          PlaneProjection planeProjection = new PlaneProjection();          planeProjection.RotationY = Math.Abs(offset) * 65 / (offset != 0 ? offset : 1);          image.Projection = planeProjection;                    double left;          double top = 50;          double center = Width / 2 - 100;          double scale = 1;            if (index == CURRENT)          {              left = center;              top = 40;              scale = 1.15;          }          else if (index > CURRENT)          {              left = center + offset * 50 + 60;          }          else          {              left = center + offset * 50 - 40;          }          //对CURRENT图片进行缩放          ScaleTransform scaleTransform = new ScaleTransform();          scaleTransform.ScaleX = scale;          scaleTransform.ScaleY = scale;          image.RenderTransform = scaleTransform;          //调整遍历图片位置          image.SetValue(Canvas.LeftProperty, left);          image.SetValue(Canvas.TopProperty, top);          image.SetValue(Canvas.ZIndexProperty, (int)(-Math.Abs(offset)) * 100);      }         //点击鼠标左键正向移动图片       private void LayoutRoot_MouseLeftButtonDown(object sender, MouseButtonEventArgs e)       {          moveIndex(1);       }        /*      * 如果将下面事件加入Canvas的MouseWheel="LayoutRoot_MouseWheel"(XAML)中,      * 页面加载后初始不能获取滚轮事件。      */      //private void LayoutRoot_MouseWheel(object sender, MouseWheelEventArgs e)      //{      //    double mouseDelta = 0;      //    mouseDelta = Math.Sign(e.Delta);      //    moveIndex((mouseDelta > 0) ? 1 : -1);      //}        //通过HtmlPage加载鼠标滚动事件,详情可参考资料<4>      private void LayoutRoot_MouseWheel(object sender, HtmlEventArgs args)      {          double mouseDelta = 0;          ScriptObject e = args.EventObject;          // Mozilla and Safari              if (e.GetProperty("detail") != null)          {              mouseDelta = ((double)e.GetProperty("detail"));          }            // IE and Opera             else if (e.GetProperty("wheelDelta") != null)              mouseDelta = ((double)e.GetProperty("wheelDelta"));            mouseDelta = Math.Sign(mouseDelta);            moveIndex((mouseDelta > 0) ? 1 : -1);      }        private void moveIndex(int value)      {          //获取目标图片位置,并确保其在图片数量范围内          TARGET += value;          TARGET = Math.Max(0, TARGET);          TARGET = Math.Min(IMAGE.Count - 1, TARGET);      }        //计时器Tick,移动到目标图片      private void timerTick(object sender, EventArgs e)      {          for (int i = 0; i < IMAGE.Count; i++)          {              Image image = IMAGE[i];              setImage(image, i);          }          CURRENT = TARGET;      }        //启动计时器      public void startShow()      {          TIMER = new DispatcherTimer();          TIMER.Interval = new TimeSpan(0, 0, 0, 0, 10);          TIMER.Tick += new EventHandler(timerTick);          TIMER.Start();      }  }

 

       至此,Nano5 的界面效果已完成,借此作品献给已世的 * MJ * 。

 

相关参考资料:

1. LinearGradientBrush类
    http://msdn.microsoft.com/zh-cn/library/system.windows.media.lineargradientbrush.aspx

2. 三维效果(透视转换)
    http://msdn.microsoft.com/zh-cn/library/dd470131(VS.95).aspx

3. DispatcherTimer 类
    http://msdn.microsoft.com/zh-cn/library/system.windows.threading.dispatchertimer(VS.95).aspx

4. How to Capture the Mouse Wheel Event
    http://blogs.silverlight.net/blogs/msnow/archive/2008/07/29/tip-of-the-day-23-how-to-capture-the-mouse-wheel-event.aspx

 

源代码下载: