private static ManualResetEvent TimeoutObject = new ManualResetEvent(false);

        /// <summary>

        /// Socket连接请求

        /// </summary>

        ///<param name="remoteEndPoint">网络端点</param>

        ///<param name="timeoutMSec">超时时间</param>

        public static void Connect(IPEndPoint remoteEndPoint, int timeoutMSec)

        {

            TimeoutObject.Reset();

            var socket = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);

            socket.BeginConnect(remoteEndPoint, CallBackMethod, socket);

            //阻塞当前线程

            if (TimeoutObject.WaitOne(timeoutMSec, false))

            {

                //MessageBox.Show("网络正常");

                Console.WriteLine("网络正常");

            }

            else

            {

                //MessageBox.Show("连接超时");

                Console.WriteLine("连接超时");

            }

        }

        //--异步回调方法

        private static void CallBackMethod(IAsyncResult asyncresult)

        {

            //使阻塞的线程继续

            TimeoutObject.Set();

        }

        private delegate string ConnectSocketDelegate(IPEndPoint ipep, Socket sock);

        private string ConnectSocket(IPEndPoint ipep, Socket sock)

        {

            string exmessage = "";

            try

            {

                sock.Connect(ipep);

            }

            catch (System.Exception ex)

            {

                exmessage = ex.Message;

            }

            finally

            {

            }

            return exmessage;

        }

        static void Main(string[] args)

        {

            string domain = "rfid.belle.cn";

            Tuple<bool, string> result = GetDomainIP(domain);

            if (result.Item1) {

                IPAddress ip = IPAddress.Parse(result.Item2);

                IPEndPoint ipep = new IPEndPoint(ip, );//IP和端口

                Connect(ipep,  );

            }

            Console.ReadLine();

        }

        private static Tuple<bool, string> GetDomainIP(string domain)

        {

            try

            {

                string Result = domain;//提取域名地址

                IPHostEntry host = Dns.GetHostByName(Result);//域名解析的IP地址

                IPAddress ip = host.AddressList[];

                string rIP = ip.ToString();

                return Tuple.Create(true, rIP);

            }

            catch

            {

                return Tuple.Create(false, "请输入正确的域名,或者您的电脑没有联互联网");

            }

        }