wpf 与winform获取鼠标坐标的差异

1. winform中以Panel为例的MouseDown事件为：
   private void panelposition_MouseDown(object sender, System.Windows.Forms.MouseEventArgs e)
   {
   　　    //分别用e.X,e.Y来获取鼠标的x，y坐标(e.X,e.Y分别为整数)
           int x=e.X;
           int y=e.Y;
   }
2. wpf中以Image为例的MouseDown事件为：
   private void imageposition_MouseDown(object sender, MouseButtonEventArgs e)
   {
           //采用e.GetPosition(IInputElement relativeTo)来获取鼠标的x，y坐标
           //以下部分来自于metadata中：
           //--------------------------------------------------------------
           // Summary:
           //     Returns the position of the mouse pointer relative to the specified element.
           //
           // Parameters:
           //   relativeTo:
           //     The element to use as the frame of reference for calculating the position
           //     of the mouse pointer.
           //
           // Returns:
           //     The x- and y-coordinates of the mouse pointer position relative to the specified
           //     object.
           public Point GetPosition(IInputElement relativeTo);
           //--------------------------------------------------------------
           //其中relativeTo为选择的对象，即在图片上面就是图片对象，窗体上面就是window对象。

                //e.GetPosition(img).X为double类型，需转换后使用。　　    
                int x = Convert.ToInt32(e.GetPosition(img).X);
                int y = Convert.ToInt32(e.GetPosition(img).Y);

        }