notifyIcon控制元件。下面的程式碼
private void MainForm_Resize(object sender, EventArgs e)
        {
            if (this.WindowState == FormWindowState.Minimized)
            {
                this.WindowState = FormWindowState.Normal;
                notifyIcon1.Visible = true;
                this.Hide();
                this.ShowInTaskbar = false;
            }
        }

        private void notifyIcon1_MouseClick(object sender, MouseEventArgs e)
        {
            if (this.ShowInTaskbar == false)
                notifyIcon1.Visible = true;

                this.ShowInTaskbar = true;
                this.Show();
                this.Activate();  
                this.WindowState = FormWindowState.Normal;
            
        }