[DllImport("user32.dll")]

         public static extern bool ReleaseCapture();

         [DllImport("user32.dll")]

         public static extern bool SendMessage(IntPtr hwnd, int wMsg, int wParam, int lParam);

         bool beginMove = false;//初始化鼠标位置

         int currentXPosition;

         int currentYPosition;

 　　　　　//获取鼠标按下时的位置

 　　　　　private void QRCode_MouseDown(object sender, MouseEventArgs e)

         {

             if (e.Button == MouseButtons.Left)

             {

                 beginMove = true;

                 currentXPosition = MousePosition.X;//鼠标的x坐标为当前窗体左上角x坐标

                 currentYPosition = MousePosition.Y;//鼠标的y坐标为当前窗体左上角y坐标

             }

         }

 　　　　　//获取鼠标移动到的位置

         private void QRCode_MouseMove(object sender, MouseEventArgs e)

         {

             if (beginMove)

             {

                 this.Left += MousePosition.X - currentXPosition;//根据鼠标x坐标确定窗体的左边坐标x

                 this.Top += MousePosition.Y - currentYPosition;//根据鼠标的y坐标窗体的顶部，即Y坐标

                 currentXPosition = MousePosition.X;

                 currentYPosition = MousePosition.Y;

             }

         }

 　　　　　//释放鼠标时的位置

         private void QRCode_MouseUp(object sender, MouseEventArgs e)

         {

             if (e.Button == MouseButtons.Left)

             {

                 currentXPosition = ; //设置初始状态

                 currentYPosition = ;

                 beginMove = false;

             }

         }