winform 点击控件拖动窗体

       private Point mPoint = new Point();

         private void 选择控件_MouseDown(object sender, MouseEventArgs e)
         {
             mPoint.X = e.X;
             mPoint.Y = e.Y;
         }

         private void 选择控件_MouseMove(object sender, MouseEventArgs e)
         {
             if (e.Button == MouseButtons.Left)
             {
                 Point myPosittion = MousePosition;
                 myPosittion.Offset(-mPoint.X, -mPoint.Y);
                 Location = myPosittion;
             }
         }