winform 无边框窗口

private Point formPoint = new Point();

public MainForm() {
    InitializeComponent();
}

private void MenuStrip_MouseMove(object sender, MouseEventArgs e) {
    if (e.Button == MouseButtons.Left) {
        Point myPosition = MousePosition;
        myPosition.Offset(-formPoint.X, -formPoint.Y);
        Location = myPosition;
    }
}

private void MenuStrip_MouseDown(object sender, MouseEventArgs e) {
    formPoint.X = e.X;
    formPoint.Y = e.Y;
}