学步园

private void Form1_MouseMove(object sender, MouseEventArgs e)
        {
            if (e.Button == MouseButtons.Left)
            {
                this.SetDesktopLocation(this.Location.X + MousePosition.X - oldx, this.Location.Y + MousePosition.Y - oldy);
                oldx = MousePosition.X;
                oldy = MousePosition.Y;
            }
        }