C# WinForm自定义拖动窗体

        private bool isMouseDown = false;
        private Point FormLocation;     //form的location
        private Point mouseOffset;      //鼠标的按下位置

        private void pnlTitle_MouseDown(object sender, MouseEventArgs e)
        {
            if (e.Button == MouseButtons.Left)
            {
                isMouseDown = true;
                FormLocation = this.Location;
                mouseOffset = Control.MousePosition;
            }
        }

        private void pnlTitle_MouseUp(object sender, MouseEventArgs e)
        {
            isMouseDown = false;
        }

        private void pnlTitle_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);
            }
        }