winform如何最小化成托盘图标

    public partial class MainForm : Form
    {
        FormWindowState fws = FormWindowState.Normal;

        public MainForm()
        {
            InitializeComponent();
            this.SizeChanged += new EventHandler(MainForm_SizeChanged);
            this.notifyIcon1.DoubleClick += new EventHandler(notifyIcon1_DoubleClick);
            this.notifyIcon1.Icon = new Icon("Virgo.ico");
            this.notifyIcon1.Visible = false;
        }

        void MainForm_SizeChanged(object sender, EventArgs e)
        {
            if (this.WindowState == FormWindowState.Minimized)
            {
                this.ShowInTaskbar = false;
                this.notifyIcon1.Visible = true;
            }
            else
            {
                fws = this.WindowState;
            }
        }

        void notifyIcon1_DoubleClick(object sender, EventArgs e)
        {
            if (this.WindowState == FormWindowState.Minimized)
            {
                this.ShowInTaskbar = true;
                this.notifyIcon1.Visible = false;
                this.WindowState = fws;
            }
        }
    }