窗体移动

                int x,y;
        void MainFormMouseDown(object sender, MouseEventArgs e)
        {
            if (e.Button == MouseButtons.Left)
            {
                x = e.X;
                y = e.Y;
            }
        }
        void MainFormMouseMove(object sender, MouseEventArgs e)
        {
            if (e.Button == MouseButtons.Left)
            {
                this.Location = new Point(this.Location.X + (e.X - x), this.Location.Y + (e.Y - y));
            }
        }