public Form1()
        {
            InitializeComponent();
            this.Load +=new EventHandler(Form1_Load);
         }
        void Form1_Load(object sender, EventArgs e)
        {
            this.notifyIcon1.Visible = true;
            this.notifyIcon1.ShowBalloonTip(20,"信息","您有新的邮件",ToolTipIcon.Info);
            //NotifyIcon.ShowBalloonTip方法:时间,标题,文本,图标;
        }