Flex Socket：

public function TioCoreTcpService(aRemoteSocketHost:String)
		{
			FTCPSocket=new XMLSocket();
			FTCPSocket.addEventListener(Event.CONNECT, OnConnectHandler);
			FTCPSocket.addEventListener(SecurityErrorEvent.SECURITY_ERROR, OnSecurityErrorHandler);
			FTCPSocket.addEventListener(Event.CLOSE, OnCloseHandler);
			FTCPSocket.addEventListener(IOErrorEvent.IO_ERROR, OnIO_Error);
			FTCPSocket.addEventListener(DataEvent.DATA, OnioTCPServiceReceiveData);
			Security.loadPolicyFile("XMLSocket://"   aRemoteSocketHost   ":"   csREMOTE_APP_TCP_PROT.toString());
			RemoteSocketHost=aRemoteSocketHost;
			FConnectTimer.addEventListener(TimerEvent.TIMER, OnConnectTimer);
		}
private function OnConnectHandler(event:Event):void
		{
			FConnectTimer.stop();
			IsSocketConnect=true;
			FIsConnectCloseEventTrigger=false;
			this.dispatchEvent(new TAppEvent(TAppEvent.TCP_CONNECT_SUCCESS));
		}

		private function OnCloseHandler(event:Event):void
		{
			FConnectTimer.start();
			this.dispatchEvent(new TAppEvent(TAppEvent.TCP_CONNECT_CLOSE));
		}

		private function OnSecurityErrorHandler(event:SecurityErrorEvent):void
		{
			FConnectTimer.start();
			this.dispatchEvent(new TAppEvent(TAppEvent.TCP_CONNECT_SECURITY_ERROR, event.text));
		}

		private function OnIO_Error(event:IOErrorEvent):void
		{
			FConnectTimer.start();
			this.dispatchEvent(new TAppEvent(TAppEvent.TCP_CONNECT_SECURITY_ERROR, event.text));
		}

		protected function OnioTCPServiceReceiveData(event:DataEvent):void
		{
			var mData:String=event.data;
			if (mData != "")
			{
				this.dispatchEvent(new TEventioTcpCoreReceive(mData));
			}
		}

C# Socket：

/// <summary>
        /// 启动TCP监听
        /// </summary>
        public void StartTcpMonitor()
        {
            isStart = false;
            if (mlistener != null)
            {
                mlistener.Stop();
            }
            if (acceptThread != null)
            {
                Thread.Sleep(30);
                acceptThread.Abort();
            }
            EndPoint mEndPoint = new IPEndPoint(IPAddress.Any, 18081);
            mlistener = new TcpListener(new IPEndPoint(IPAddress.Any, 18081));
            isStart = true;
            mlistener.Start();
            acceptThread = new Thread(new ThreadStart(AcceptWorkThread));
            acceptThread.IsBackground = true;
            acceptThread.Start();
        }

        public void StopTcpMonitor()
        {
            try
            {
                isStart = false;
                foreach (KeyValuePair<string, Thread> value in mThreadDictionary)
                {
                    Thread.Sleep(30);
                    value.Value.Abort();
                }
                mThreadDictionary.Clear();
                foreach (KeyValuePair<EndPoint, Socket> value in mtcpSocketDictionary)
                {
                    value.Value.Close();
                }
                mtcpSocketDictionary.Clear();
                mlistener.Stop();
                acceptThread.Abort();
            }
            catch
            {
            }
        }

        private void AcceptWorkThread()
        {
            if (isStart == true)
            {
                while (isStart)
                {
                    try
                    {
                        Socket tcpsocket = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
                        tcpsocket = mlistener.AcceptSocket();
                        receivethread = new Thread(new ParameterizedThreadStart(ThreadCliendHandler));
                        receivethread.IsBackground = true;
                        receivethread.Start(tcpsocket);
                    }
                    catch (Exception ex)
                    {
                        ErrorLog.WriteErrorLog("
"   System.DateTime.Now.ToString()   " 错误日志："   ex.ToString(), GlobalApplicationsCore.GetAppliation().errorLogPath);
                        throw ex;
                    }
                    finally
                    {
                        tcpConnectionThreadCount  ;
                        if (TcpThreadNumberEvent != null)
                        {
                            TcpThreadNumberEvent(0, tcpConnectionThreadCount);
                        }
                    }
                }
            }
        }

Web端Flex完整项目下载：http://www.pengyaou.com/ChatOnline/DownLoad/Chat.rar

服务端C#完整项目下载：http://www.pengyaou.com/ChatOnline/DownLoad/ChatServier.rar