public class Message

    {

        Form1 mainfrom = null;

        public Message() { }

        public Message(Form1 form)

        {

            mainfrom = form;

        }

        public bool StartReceive(int port)

        {

            try

            {

                IPEndPoint iep = new IPEndPoint(IPAddress.Loopback, port);

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

                tcpServer.Bind(iep);

                tcpServer.Listen();

                tcpServer.BeginAccept(new AsyncCallback(Accept), tcpServer);

                return true;

            }

            catch (Exception ex) { return false; }

        }

        private void Accept(IAsyncResult ia)

        {

            Socket socket = ia.AsyncState as Socket;

            var client = socket.EndAccept(ia);

            byte[] buf = new byte[];

            socket.BeginAccept(new AsyncCallback(Accept), socket);

            StateObject state = new StateObject();

            state.workSocket = client;

            try

            {

                client.BeginReceive(state.buffer, , StateObject.BufferSize, SocketFlags.None, new AsyncCallback(Receive), state);

            }

            catch (Exception ex)

            {

                //Console.WriteLine("监听请求时出错：\r\n" + ex.ToString());

            }

        }

        private void Receive(IAsyncResult ia)

        {

            StateObject state = ia.AsyncState as StateObject;

            if (state == null)

            {

                return;

            }

            Socket client = state.workSocket;

            if (client == null)

            {

                return;

            }

            try

            {

                int count = client.EndReceive(ia);

                if (count > )

                {

                    try

                    {

                        client.BeginReceive(state.buffer, , StateObject.BufferSize, SocketFlags.None, new AsyncCallback(Receive), client);

                        string context = Encoding.GetEncoding("gb2312").GetString(state.buffer, , count);

                        //显示接收消息

                        mainfrom.LoginFormTextChange(context);

                    }

                    catch (Exception ex)

                    {

                        //Console.WriteLine("接收的数据出错:\r\n{0}", ex.ToString());

                    }

                }

            }

            catch (Exception err)

            {

            }

        }

        public void SendMessage(int port, string m)

        {

            System.Text.Encoding CharSet = System.Text.Encoding.GetEncoding("gb2312");

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

            try

            {

                tcpClient.Connect(IPAddress.Loopback, port);

                string sendmsg = m;

                byte[] buff = CharSet.GetBytes(sendmsg);

                tcpClient.Send(buff, buff.Length, );

            }

            catch (SocketException e)

            {

            }

        }

    }

    public class StateObject

    {

        // Client  socket.

        public Socket workSocket = null;

        // Size of receive buffer.

        public const int BufferSize = ;

        // Receive buffer.

        public byte[] buffer = new byte[BufferSize];

        // Received data string.

        public StringBuilder sb = new StringBuilder();

    }