private static int port = Convert.ToInt32(ConfigurationManager.AppSettings["LogServerPort"]);

        public static void StartListening()
        {
            IPAddress ipAddress = System.Net.IPAddress.Parse("0.0.0.0");
            IPEndPoint localEndPoint = new IPEndPoint(ipAddress, port);
            // Create a TCP/IP socket.
            Socket listener = new Socket(AddressFamily.InterNetwork,
                SocketType.Stream, ProtocolType.Tcp);

            // Bind the socket to the local endpoint and 
            // listen for incoming connections.
            try
            {
                listener.Bind(localEndPoint);
                listener.Listen(1000);

                // Start listening for connections.
                while (true)
                {
                    try
                    {
                            Socket handler = listener.Accept();      //accept  有三次握手過程，第一次握手成功，Accept()方法就停止阻塞
                            Thread t = new Thread(resMsg);
                            t.IsBackground = true;
                            t.Start(handler);

                    }
                    catch (Exception ex)
                    {
                        BaseFunc.WriteInLog(ex.Message + ex.StackTrace);
                        Thread.Sleep(10000); 
                    }
                   
                }

            }
            catch (Exception e)
            {
                BaseFunc.WriteInLog(e.Message + e.StackTrace);
            }

        }
 

        /// <summary>
        /// 迴圈接收客戶端發來的訊息
        /// </summary>
        /// <param name="obj"></param>
        static void resMsg(object obj)
        {
            int count = 0;


            try
            {
                Socket uSocket = obj as Socket;
                //1.防止Accept第三次握手沒有成功，Receive()方法就一直處於阻塞狀態！！！報錯資訊（由於連線方在一段時間後沒有正確答覆或連線的主機沒有反應，連線嘗試失敗）        //2.接收超時限制
            uSocket.ReceiveTimeout = 3000; //很重要！！！
                //開始呼叫Receive()函式
                ......   

            }
        }
 

TCP三次握手連線