退出winform时弹出确认按钮

 /// <summary>
        /// 窗体关闭事件的处理程序
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void Form1_FormClosing(object sender, FormClosingEventArgs e)
        {
            if (MessageBox.Show("确实要退出服务程序吗？", "退出程序", MessageBoxButtons.OKCancel) == DialogResult.OK)
            {
                if ((MainTCPListenerThread != null) && MainTCPListenerThread.IsAlive)
                {
                    StopTCPServerFun();
                    MainTCPListenerThread.Abort();
                }
                Environment.Exit(0);
            }
            else
            {
                e.Cancel=true;
            }
        }