程序代码：

private void Form1_SizeChanged(object sender, EventArgs e)
        {
            if (this.WindowState == FormWindowState.Minimized)
            {
                this.ShowInTaskbar = false;
                this.Hide();
                this.notifyIcon1.Visible = true;
                this.notifyIcon1.Icon = new Icon(@"C:\icon.ico");
                this.notifyIcon1.ShowBalloonTip(3000);
            }

        }

        private void notifyIcon1_MouseDoubleClick(object sender, MouseEventArgs e)
        {           
            this.WindowState = FormWindowState.Normal;
            this.ShowInTaskbar = true;
            this.Show();
            this.notifyIcon1.Visible = false;
        }