兼容Silverlight4的实用的Silverlight可拖放工具类源代码

public static class DragDrop
{
    private static bool IsDragging = false;
    private static Point curPoint;
    private const int MAX_ZINDEX = 99999;
    private const double CURRENT_OPACITY = 0.5;
    private static int lastZIndex;
    private static double lastOpacity;

    private static void sender_MouSELEftButtonDown(object sender,MouseButtonEventArgs E)
    {
        UIElement uiElement = sender as UIElement;
        if (uiElement != null)
        {
            uiElement.CaptureMouse();
            lastZIndex = (int)uiElement.GetValue(Canvas.ZIndexProperty);
            uiElement.SETVALue(Canvas.ZIndexProperty,MAX_ZINDEX);
            lastOpacity = uiElement.opacity;
            uiElement.opacity = CURRENT_OPACITY;
            IsDragging = true;
            curPoint = new Point(e.GetPosition(null).X,e.GetPosition(null).Y);
        }
    }

    private static void sender_MouseMove(object sender,MouseEventArgs E)
    {
        if (!IsDragging)
        {
            return;
        }

        UIElement uiElement = sender as UIElement;
        if (uiElement != null)
        {
            double currentLeft = (double)uiElement.GetValue(Canvas.LeftProperty);
            double currentTop = (double)uiElement.GetValue(Canvas.TopProperty);

            double newLeft = (double)currentLeft + e.GetPosition(null).X - curPoint.X;
            double newTop = (double)currentTop + e.GetPosition(null).Y - curPoint.Y;

            uiElement.SETVALue(Canvas.LeftProperty,newLeft);
            uiElement.SETVALue(Canvas.TopProperty,newTop);
            curPoint = new Point(e.GetPosition(null).X,e.GetPosition(null).Y);
        }
    }

    private static void sender_MouSELEftButtonUp(object sender,MouseButtonEventArgs E)
    {
        UIElement uiElement = sender as UIElement;
        if (uiElement != null)
        {
            uiElement.ReleaseMouseCapture();
            IsDragging = false;
            uiElement.SETVALue(Canvas.ZIndexProperty,lastZIndeX);
            uiElement.opacity = lastOpacity;
        }
    }

    public static void Load(UIElement sender)
    {
        sender.MouSELEftButtonDown += new MouseButtonEventHandler(sender_MouSELEftButtonDown);
        sender.MouSELEftButtonUp += new MouseButtonEventHandler(sender_MouSELEftButtonUp);
        sender.MouseMove += new MouseEventHandler(sender_MouseMovE);
    }

    public static void UnLoad(UIElement sender)
    {
        sender.MouSELEftButtonDown -= new MouseButtonEventHandler(sender_MouSELEftButtonDown);
        sender.MouSELEftButtonUp -= new MouseButtonEventHandler(sender_MouSELEftButtonUp);
        sender.MouseMove -= new MouseEventHandler(sender_MouseMovE);
    }
}

DragDrop工具类的使用方法：

DragDrop.Load(LayoutRoot);

DragDrop是一个静态类，使用起来非常简单，以上只要一行代码就可以实现对Grid控件的拖放操作了。

希望对大家有所帮助~！