/// <summary>

     /// 可触摸滚动的ScrollViewer控件

     /// </summary>

     public class TouchableScrollViewer : ScrollViewer

     {

         //触摸点的坐标

         Point _startPosition;

         //滚动条当前位置

         double _startVerticalOffset;

         double _startHorizontalOffset;

         public TouchableScrollViewer()

         {

             TouchDown += TouchableScrollViewer_TouchDown;

             TouchUp += TouchableScrollViewer_TouchUp;

         }

         private void TouchableScrollViewer_TouchDown(object sender, TouchEventArgs e)

         {

             //添加触摸移动监听

             TouchMove -= TouchableScrollViewer_TouchMove;

             TouchMove += TouchableScrollViewer_TouchMove;

             //获取ScrollViewer滚动条当前位置

             _startVerticalOffset = VerticalOffset;

             _startHorizontalOffset = HorizontalOffset;

             //获取相对于ScrollViewer的触摸点位置

             TouchPoint point = e.GetTouchPoint(this);

             _startPosition = point.Position;

         }

         private void TouchableScrollViewer_TouchUp(object sender, TouchEventArgs e)

         {

             //注销触摸移动监听

             TouchMove -= TouchableScrollViewer_TouchMove;

         }

         private void TouchableScrollViewer_TouchMove(object sender, TouchEventArgs e)

         {

             //获取相对于ScrollViewer的触摸点位置

             TouchPoint endPoint = e.GetTouchPoint(this);

             //计算相对位置

             double diffOffsetY = endPoint.Position.Y - _startPosition.Y;

             double diffOffsetX = endPoint.Position.X - _startPosition.X;

             //ScrollViewer滚动到指定位置(指定位置=起始位置-移动的偏移量，滚动方向和手势方向相反)

             ScrollToVerticalOffset(_startVerticalOffset - diffOffsetY);

             ScrollToHorizontalOffset(_startHorizontalOffset - diffOffsetX);

         }

     }