Tcp异步通讯实例

 服务端：

using System;
using System.Net;
using System.Net.Sockets;
using System.Text;
using System.Threading;

//////////////////////////////////////////////////////////////////
/*                同步与异步小知识
 *
 * 所谓同步，可以理解为在执行完一个函数或方法之后，
 * 一直等待系统返回值或消息，这时程序是出于阻塞的，
 * 只有接收到返回的值或消息后才往下执行其他的命令。  
 * 所谓异步，执行完函数或方法后，不必阻塞性地等待返回值或消息，
 * 只需要向系统委托一个异步过程，那么当系统接收到返回值或消息时，
 * 系统会自动触发委托的异步过程，从而完成一个完整的流程。
 */
//////////////////////////////////////////////////////////////////

//////////////////////////////////////////////////////////////////
//
//                     异步socket例子------服务器端。
//                       2009-11-27
//
//////////////////////////////////////////////////////////////////

//细致、深刻、耐心的理解这种处理的机制。以便以后可以熟练的应用到项目中去。

namespace AsyncSocketServer
{
 
    // State object for reading client data asynchronously
    public class StateObject
    {
        // Client  socket.
        public Socket workSocket = null;
        // Size of receive buffer.
        public const int BufferSize = 1024;
        // Receive buffer.
        public byte[] buffer = new byte[BufferSize];
        // Received data string.
        public StringBuilder sb = new StringBuilder();
    }

    public class AsynchronousSocketListener
    {
        // Thread signal.
        public static ManualResetEvent allDone = new ManualResetEvent(false);

        public AsynchronousSocketListener()
        {
        }

        /// <summary>
        /// 开始监听
        /// </summary>
        public static void StartListening()
        {
            // Data buffer for incoming data.
            byte[] bytes = new Byte[1024];

            // Establish the local endpoint for the socket.
            // The DNS name of the computer
            // running the listener is "host.contoso.com".
            IPHostEntry ipHostInfo = Dns.Resolve(Dns.GetHostName());
            IPAddress ipAddress = ipHostInfo.AddressList[0];
            IPEndPoint localEndPoint = new IPEndPoint(ipAddress, 11000);

            // 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(100);//等待队列中的最大数。

                while (true)
                {
                    // Set the event to nonsignaled state.设置为无信号状态，线程阻止
                    allDone.Reset();

                    // Start an asynchronous socket to listen for connections.
                    Console.WriteLine("Waiting for a connection...");
                    //开始一个异步操作接收一个传入的连接尝试
                    listener.BeginAccept(
                        new AsyncCallback(AcceptCallback),
                        listener);

                    // Wait until a connection is made before continuing.阻止当前线程，直到收到信号
                    allDone.WaitOne();
                }

            }
            catch (Exception e)
            {
                Console.WriteLine(e.ToString());
            }

            Console.WriteLine("/nPress ENTER to continue...");
            Console.Read();

        }

        /// <summary>
        /// 接收数据的回调函数
        /// </summary>
        /// <param name="ar">异步返回的结果</param>
        public static void AcceptCallback(IAsyncResult ar)
        {
            // Signal the main thread to continue.主线程继续执行
            allDone.Set();

            // Get the socket that handles the client request.
            Socket listener = (Socket)ar.AsyncState;
            //异步接受传入的连接尝试，并创建一个新的socket来处理远程主机通讯
            Socket handler = listener.EndAccept(ar);

            // Create the state object.
            StateObject state = new StateObject();
            state.workSocket = handler;
            handler.BeginReceive(state.buffer, 0, StateObject.BufferSize, 0,
                new AsyncCallback(ReadCallback), state);
        }

        /// <summary>
        /// 读取数据的回调函数
        /// </summary>
        /// <param name="ar"></param>
        public static void ReadCallback(IAsyncResult ar)
        {
            String content = String.Empty;

            // Retrieve the state object and the handler socket
            // from the asynchronous state object.
            StateObject state = (StateObject)ar.AsyncState;
            Socket handler = state.workSocket;

            // Read data from the client socket. 从client socket读取数据。
            int bytesRead = handler.EndReceive(ar);

            if (bytesRead > 0)
            {
                // There  might be more data, so store the data received so far.
                state.sb.Append(Encoding.ASCII.GetString(
                    state.buffer, 0, bytesRead));

                // Check for end-of-file tag. If it is not there, read
                // more data.
                content = state.sb.ToString();
                if (content.IndexOf("<EOF>") > -1)
                {
                    // All the data has been read from the
                    // client. Display it on the console.
                    Console.WriteLine("Read {0} bytes from socket. /n Data : {1}",
                        content.Length, content);
                    // Echo the data back to the client.
                    Send(handler, content);
                }
                else
                {
                    // Not all data received. Get more. 还没有完全读完数据，继续读。
                    handler.BeginReceive(state.buffer, 0, StateObject.BufferSize, 0,
                    new AsyncCallback(ReadCallback), state);
                }
            }
        }

        /// <summary>
        /// 给远程主机发送数据。
        /// </summary>
        /// <param name="handler">远程socket</param>
        /// <param name="data">数据内容</param>
        private static void Send(Socket handler, String data)
        {
            // Convert the string data to byte data using ASCII encoding.
            byte[] byteData = Encoding.ASCII.GetBytes(data);

            // Begin sending the data to the remote device.
            handler.BeginSend(byteData, 0, byteData.Length, 0,
                new AsyncCallback(SendCallback), handler);
        }

        /// <summary>
        /// 发送数据回调函数。
        /// </summary>
        /// <param name="ar"></param>
        private static void SendCallback(IAsyncResult ar)
        {
            try
            {
                // Retrieve the socket from the state object.
                Socket handler = (Socket)ar.AsyncState;

                // Complete sending the data to the remote device.发送数据。
                int bytesSent = handler.EndSend(ar);
                Console.WriteLine("Sent {0} bytes to client.", bytesSent);

                handler.Shutdown(SocketShutdown.Both);
                handler.Close();

            }
            catch (Exception e)
            {
                Console.WriteLine(e.ToString());
            }
        }

        public static int Main(String[] args)
        {
            StartListening();
            return 0;
        }
    }
}

客户端：

using System;
using System.Net;
using System.Net.Sockets;
using System.Threading;
using System.Text;

////////////////////////////////////////////////////////
//
//        异步socket例子-----客户端。
//            2009-11-27
//
////////////////////////////////////////////////////////

namespace AsyncSocketClient
{
 
    // State object for receiving data from remote device.
    /// <summary>
    /// 从远程主机接收数据的状态对象。
    /// </summary>
    public class StateObject
    {
        // Client socket.
        /// <summary>
        /// 远程主机的socket
        /// </summary>
        public Socket workSocket = null;
        // Size of receive buffer.
        public const int BufferSize = 256;
        // Receive buffer.
        public byte[] buffer = new byte[BufferSize];
        // Received data string.
        public StringBuilder sb = new StringBuilder();
    }

    public class AsynchronousClient
    {
        // The port number for the remote device.
        private const int port = 11000;

        // ManualResetEvent instances signal completion.
        /// <summary>
        /// 连接信号
        /// </summary>
        private static ManualResetEvent connectDone =
            new ManualResetEvent(false);
        /// <summary>
        /// 发送信号
        /// </summary>
        private static ManualResetEvent sendDone =
            new ManualResetEvent(false);
        /// <summary>
        /// 接收信号
        /// </summary>
        private static ManualResetEvent receiveDone =
            new ManualResetEvent(false);

        // The response from the remote device.
        private static String response = String.Empty;

        private static void StartClient()
        {
            // Connect to a remote device.
            try
            {
                // Establish the remote endpoint for the socket.
                // The name of the
                // remote device is "host.contoso.com".
                IPHostEntry ipHostInfo = Dns.Resolve(Dns.GetHostName());
                IPAddress ipAddress = ipHostInfo.AddressList[0];
                IPEndPoint remoteEP = new IPEndPoint(ipAddress, port);

                // Create a TCP/IP socket.
                Socket client = new Socket(AddressFamily.InterNetwork,
                    SocketType.Stream, ProtocolType.Tcp);

                // Connect to the remote endpoint.异步连接到远程主机
                client.BeginConnect(remoteEP,
                    new AsyncCallback(ConnectCallback), client);
                connectDone.WaitOne();//阻止线程，等待连接完成信号

                // Send test data to the remote device.
                Send(client, "This is a test<EOF>");
                sendDone.WaitOne();//阻止线程，等待发送完成信号

                // Receive the response from the remote device.
                Receive(client);
                receiveDone.WaitOne();//阻止线程，等待接收完成信号

                // Write the response to the console.
                Console.WriteLine("Response received : {0}", response);

                // Release the socket.
                client.Shutdown(SocketShutdown.Both);
                client.Close();

            }
            catch (Exception e)
            {
                Console.WriteLine(e.ToString());
            }
        }

        /// <summary>
        /// 连接完成回调函数
        /// </summary>
        /// <param name="ar"></param>
        private static void ConnectCallback(IAsyncResult ar)
        {
            try
            {
                // Retrieve the socket from the state object.
                Socket client = (Socket)ar.AsyncState;

                // Complete the connection.
                client.EndConnect(ar);

                Console.WriteLine("Socket connected to {0}",
                    client.RemoteEndPoint.ToString());

                // Signal that the connection has been made.
                connectDone.Set();
            }
            catch (Exception e)
            {
                Console.WriteLine(e.ToString());
            }
        }

        /// <summary>
        /// 接收数据。
        /// </summary>
        /// <param name="client"></param>
        private static void Receive(Socket client)
        {
            try
            {
                // Create the state object.
                StateObject state = new StateObject();
                state.workSocket = client;

                // Begin receiving the data from the remote device.
                client.BeginReceive(state.buffer, 0, StateObject.BufferSize, 0,
                    new AsyncCallback(ReceiveCallback), state);
            }
            catch (Exception e)
            {
                Console.WriteLine(e.ToString());
            }
        }
        /// <summary>
        /// 接收完成回调函数
        /// </summary>
        /// <param name="ar"></param>
        private static void ReceiveCallback(IAsyncResult ar)
        {
            try
            {
                // Retrieve the state object and the client socket
                // from the asynchronous state object.
                StateObject state = (StateObject)ar.AsyncState;
                Socket client = state.workSocket;

                // Read data from the remote device.
                int bytesRead = client.EndReceive(ar);

                if (bytesRead > 0)
                {
                    // There might be more data, so store the data received so far.
                    state.sb.Append(Encoding.ASCII.GetString(state.buffer, 0, bytesRead));

                    // Get the rest of the data.
                    client.BeginReceive(state.buffer, 0, StateObject.BufferSize, 0,
                        new AsyncCallback(ReceiveCallback), state);
                }
                else
                {
                    // All the data has arrived; put it in response.
                    if (state.sb.Length > 1)
                    {
                        response = state.sb.ToString();
                    }
                    // Signal that all bytes have been received.
                    receiveDone.Set();
                }
            }
            catch (Exception e)
            {
                Console.WriteLine(e.ToString());
            }
        }

        /// <summary>
        /// 发送数据
        /// </summary>
        /// <param name="client"></param>
        /// <param name="data"></param>
        private static void Send(Socket client, String data)
        {
            // Convert the string data to byte data using ASCII encoding.
            byte[] byteData = Encoding.ASCII.GetBytes(data);

            // Begin sending the data to the remote device.
            client.BeginSend(byteData, 0, byteData.Length, 0,
                new AsyncCallback(SendCallback), client);
        }

        /// <summary>
        /// 发送数据完成回调函数
        /// </summary>
        /// <param name="ar"></param>
        private static void SendCallback(IAsyncResult ar)
        {
            try
            {
                // Retrieve the socket from the state object.
                Socket client = (Socket)ar.AsyncState;

                // Complete sending the data to the remote device.
                int bytesSent = client.EndSend(ar);
                Console.WriteLine("Sent {0} bytes to server.", bytesSent);

                // Signal that all bytes have been sent.
                sendDone.Set();
            }
            catch (Exception e)
            {
                Console.WriteLine(e.ToString());
            }
        }

        public static int Main(String[] args)
        {
            StartClient();
            return 0;
        }
    }
}