如何创建没有表单的notifyIcon？ [重复]

public Form2()
    {
        InitializeComponent();
        notifyIcon1.Icon = SystemIcons.Asterisk;
        notifyIcon1.DoubleClick += new EventHandler(notifyIcon1_DoubleClick);// to bring it back
        this.Resize += new EventHandler(Form2_Resize);// to move it to tray
    }

    void notifyIcon1_DoubleClick(object sender, EventArgs e)
    {
        Show();
        this.BringToFront();
        this.WindowState = FormWindowState.Normal;
    }

    void Form2_Resize(object sender, EventArgs e)
    {
        if (this.WindowState ==FormWindowState.Minimized)
            Hide();
    }

 this.WindowState = FormWindowState.Minimized;