设置鼠标可以移动窗体

       #region 设置鼠标可以移动
        private bool ismouseDown = false;//判断是否按下鼠标
        private Point mouseOffset;//记录鼠标坐标
        private void Login_MouseDown(object sender, MouseEventArgs e)
        {
            int xOffset;   //定义X坐标

            int yOffset;   //定义Y坐标

            if (e.Button == MouseButtons.Left)
            {   //如果鼠标的左键点击了，则将坐标分别进行相应的移动

                xOffset = -e.X;

                yOffset = -e.Y;

                mouseOffset = new Point(xOffset, yOffset);

                ismouseDown = true;   //将mousedowm变量置为true，说明mousedown了

            }

        }

        private void Login_MouseMove(object sender, MouseEventArgs e)
        {
            //如果鼠标移动了

            if (ismouseDown)
            {

                //获取坐标的位置

                Point MousePos = Control.MousePosition;

                MousePos.Offset(mouseOffset.X, mouseOffset.Y);

                Location = MousePos;  //此时获取的坐标的值即为鼠标的坐标

            }

        }

        private void Login_MouseUp(object sender, MouseEventArgs e)
        {
            //如果鼠标按键松开了，则将mousedown属性置为false，说明鼠标的左键已经松开

            if (e.Button == MouseButtons.Left)

                ismouseDown = false;

        }
    }
        #endregion