C#中移动无边框窗体

为了美观，自己用Panel做了一个标题栏，如下图白色的上边栏，直接贴代码

        /// 

        /// 鼠标左键按下
        /// 
        /// 
        /// 
        private void panel3_MouseDown(object sender, MouseEventArgs e)
        {
            if (e.Button == MouseButtons.Left)
            {
                isMouseDown = true;
                FormLocation = this.Location;
                mouseOffset = Control.MousePosition;
            }
        }
        /// 

        /// 鼠标移动
        /// 
        /// 
        /// 
        private void panel3_MouseMove(object sender, MouseEventArgs e)
        {
            int x = 0;
            int y = 0;
            if (isMouseDown)
            {
                Point pt = Control.MousePosition;
                x = mouseOffset.X - pt.X;
                y = mouseOffset.Y - pt.Y;

                this.Location = new Point(FormLocation.X - x, FormLocation.Y - y);
            }
        }
        /// 

        /// 鼠标左键松开
        /// 
        /// 
        /// 
        private void panel3_MouseUp(object sender, MouseEventArgs e)
        {
            isMouseDown = false;//全局变量防止鼠标没有按下左键窗体也跟着移动
        }