C#网络编程系列文章(五)之Socket实现异步UDP服务器

文章系列目录

C#网络编程系列文章(一)之Socket实现异步TCP服务器 

C#网络编程系列文章(二)之Socket实现同步TCP服务器

C#网络编程系列文章(三)之TcpListener实现异步TCP服务器

C#网络编程系列文章(五)之Socket实现异步UDP服务器

C#网络编程系列文章(六)之Socket实现同步UDP服务器

C#网络编程系列文章(七)之UdpClient实现异步UDP服务器

C#网络编程系列文章(八)之UdpClient实现同步UDP服务器

参考路径：

https://blog.csdn.net/zhujunxxxxx/article/details/44258719

代码下载地址

http://download.csdn.net/detail/zhujunxxxxx/8510991

本文介绍
在.Net中，System.Net.Sockets 命名空间为需要严密控制网络访问的开发人员提供了 Windows Sockets (Winsock) 接口的托管实现。System.Net 命名空间中的所有其他网络访问类都建立在该套接字Socket实现之上，如TCPClient、TCPListener 和 UDPClient 类封装有关创建到 Internet 的 TCP 和 UDP 连接的详细信息；NetworkStream类则提供用于网络访问的基础数据流等，常见的许多Internet服务都可以见到Socket的踪影，如Telnet、Http、Email、Echo等，这些服务尽管通讯协议Protocol的定义不同，但是其基础的传输都是采用的Socket。 其实，Socket可以象流Stream一样被视为一个数据通道，这个通道架设在应用程序端（客户端）和远程服务器端之间，而后，数据的读取（接收）和写入（发送）均针对这个通道来进行。 可见，在应用程序端或者服务器端创建了Socket对象之后，就可以使用Send/SentTo方法将数据发送到连接的Socket,或者使用Receive/ReceiveFrom方法接收来自连接Socket的数据； 针对Socket编程，.NET 框架的 Socket 类是 Winsock32 API 提供的套接字服务的托管代码版本。其中为实现网络编程提供了大量的方法，大多数情况下，Socket 类方法只是将数据封送到它们的本机 Win32 副本中并处理任何必要的安全检查。如果你熟悉Winsock API函数，那么用Socket类编写网络程序会非常容易，当然，如果你不曾接触过，也不会太困难，跟随下面的解说，你会发觉使用Socket类开发windows
 网络应用程序原来有规可寻，它们在大多数情况下遵循大致相同的步骤。
本节介绍使用Socket来实现一个高性能的异步UDP服务器，实际上UDP是不分客户机和服务器的，但是我们有的时候和服务器通讯就是使用UDP来进行的。
Socket异步UDP服务器：

using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

using System.Net;

using System.Net.Sockets;

 

namespace NetFrame.Net.UDP.Sock.Asynchronous

{

    /// <summary>

    /// SOCKET实现异步UDP服务器

    /// </summary>

    public class AsyncSocketUDPServer

    {

        #region Fields

        /// <summary>

        /// 服务器程序允许的最大客户端连接数

        /// </summary>

        private int _maxClient;

 

        /// <summary>

        /// 当前的连接的客户端数

        /// </summary>

        //private int _clientCount;

 

        /// <summary>

        /// 服务器使用的同步socket

        /// </summary>

        private Socket _serverSock;

 

        /// <summary>

        /// 客户端会话列表

        /// </summary>

        //private List<AsyncUDPSocketState> _clients;

 

        private bool disposed = false;

 

        /// <summary>

        /// 数据接受缓冲区

        /// </summary>

        private byte[] _recvBuffer;

 

        #endregion

 

        #region Properties

 

        /// <summary>

        /// 服务器是否正在运行

        /// </summary>

        public bool IsRunning { get; private set; }

        /// <summary>

        /// 监听的IP地址

        /// </summary>

        public IPAddress Address { get; private set; }

        /// <summary>

        /// 监听的端口

        /// </summary>

        public int Port { get; private set; }

        /// <summary>

        /// 通信使用的编码

        /// </summary>

        public Encoding Encoding { get; set; }

 

        #endregion

 

        #region 构造函数

 

        /// <summary>

        /// 异步Socket UDP服务器

        /// </summary>

        /// <param name="listenPort">监听的端口</param>

        public AsyncSocketUDPServer(int listenPort)

            : this(IPAddress.Any, listenPort,1024)

        {

        }

 

        /// <summary>

        /// 异步Socket UDP服务器

        /// </summary>

        /// <param name="localEP">监听的终结点</param>

        public AsyncSocketUDPServer(IPEndPoint localEP)

            : this(localEP.Address, localEP.Port,1024)

        {

        }

 

        /// <summary>

        /// 异步Socket UDP服务器

        /// </summary>

        /// <param name="localIPAddress">监听的IP地址</param>

        /// <param name="listenPort">监听的端口</param>

        /// <param name="maxClient">最大客户端数量</param>

        public AsyncSocketUDPServer(IPAddress localIPAddress, int listenPort, int maxClient)

        {

            this.Address = localIPAddress;

            this.Port = listenPort;

            this.Encoding = Encoding.Default;

 

            _maxClient = maxClient;

            //_clients = new List<AsyncUDPSocketState>();

            _serverSock = new Socket(localIPAddress.AddressFamily, SocketType.Dgram, ProtocolType.Udp);

 

            _recvBuffer=new byte[_serverSock.ReceiveBufferSize];

        }

 

        #endregion

 

        #region Method

        /// <summary>

        /// 启动服务器

        /// </summary>

        /// <returns>异步TCP服务器</returns>

        public void Start()

        {

            if (!IsRunning)

            {

                IsRunning = true;

                _serverSock.Bind(new IPEndPoint(this.Address, this.Port));

                //_serverSock.Connect(new IPEndPoint(IPAddress.Any, 0));

 

                AsyncSocketUDPState so = new AsyncSocketUDPState();

                so.workSocket = _serverSock;

 

                _serverSock.BeginReceiveFrom(so.buffer, 0, so.buffer.Length, SocketFlags.None,

                    ref so.remote, new AsyncCallback(ReceiveDataAsync), null);

 

 

                //EndPoint sender = new IPEndPoint(IPAddress.Any, 0);

 

                //_serverSock.BeginReceiveFrom(_recvBuffer, 0, _recvBuffer.Length, SocketFlags.None,

                //    ref sender, new AsyncCallback(ReceiveDataAsync), sender);

 

                //BeginReceive 和 BeginReceiveFrom的区别是什么

                /*_serverSock.BeginReceive(_recvBuffer, 0, _recvBuffer.Length, SocketFlags.None,

                    new AsyncCallback(ReceiveDataAsync), null);*/

            }

        }

 

        /// <summary>

        /// 停止服务器

        /// </summary>

        public void Stop()

        {

            if (IsRunning)

            {

                IsRunning = false;

                _serverSock.Close();

                //TODO 关闭对所有客户端的连接

 

            }

        }

 

        /// <summary>

        /// 接收数据的方法

        /// </summary>

        /// <param name="ar"></param>

        private void ReceiveDataAsync(IAsyncResult ar)

        {

            AsyncSocketUDPState so = ar.AsyncState as AsyncSocketUDPState;

            //EndPoint sender = new IPEndPoint(IPAddress.Any, 0);

            int len = -1;

            try

            {

                len = _serverSock.EndReceiveFrom(ar, ref so.remote);

 

                //len = _serverSock.EndReceiveFrom(ar, ref sender);

 

                //EndReceiveFrom 和 EndReceive区别

                //len = _serverSock.EndReceive(ar);

                //TODO 处理数据

 

                //触发数据收到事件

                RaiseDataReceived(so);

            }

            catch (Exception)

            {

                //TODO 处理异常

                RaiseOtherException(so);

            }

            finally

            {

                if (IsRunning && _serverSock != null)

                    _serverSock.BeginReceiveFrom(so.buffer, 0, so.buffer.Length, SocketFlags.None,

                ref so.remote, new AsyncCallback(ReceiveDataAsync), so);

            }

        }

        /// <summary>

        /// 发送数据

        /// </summary>

        /// <param name="msg"></param>

        /// <param name="remote"></param>

        public void Send(string msg,EndPoint remote)

        {

            byte[] data = Encoding.Default.GetBytes(msg);

            try

            {

                RaisePrepareSend(null);

                _serverSock.BeginSendTo(data, 0, data.Length, SocketFlags.None, remote, new AsyncCallback(SendDataEnd), _serverSock);

            }

            catch (Exception)

            {

                //TODO 异常处理

                RaiseOtherException(null);

            }

        }

 

        private void SendDataEnd(IAsyncResult ar)

        {

            ((Socket)ar.AsyncState).EndSendTo(ar);

            RaiseCompletedSend(null);

        }

 

        #endregion

 

        #region 事件

        /// <summary>

        /// 接收到数据事件

        /// </summary>

        public event EventHandler<AsyncSocketUDPEventArgs> DataReceived;

 

        private void RaiseDataReceived(AsyncSocketUDPState state)

        {

            if (DataReceived != null)

            {

                DataReceived(this, new AsyncSocketUDPEventArgs(state));

            }

        }

 

        /// <summary>

        /// 发送数据前的事件

        /// </summary>

        public event EventHandler<AsyncSocketUDPEventArgs> PrepareSend;

 

        /// <summary>

        /// 触发发送数据前的事件

        /// </summary>

        /// <param name="state"></param>

        private void RaisePrepareSend(AsyncSocketUDPState state)

        {

            if (PrepareSend != null)

            {

                PrepareSend(this, new AsyncSocketUDPEventArgs(state));

            }

        }

 

        /// <summary>

        /// 数据发送完毕事件

        /// </summary>

        public event EventHandler<AsyncSocketUDPEventArgs> CompletedSend;

 

        /// <summary>

        /// 触发数据发送完毕的事件

        /// </summary>

        /// <param name="state"></param>

        private void RaiseCompletedSend(AsyncSocketUDPState state)

        {

            if (CompletedSend != null)

            {

                CompletedSend(this, new AsyncSocketUDPEventArgs(state));

            }

        }

 

        /// <summary>

        /// 网络错误事件

        /// </summary>

        public event EventHandler<AsyncSocketUDPEventArgs> NetError;

        /// <summary>

        /// 触发网络错误事件

        /// </summary>

        /// <param name="state"></param>

        private void RaiseNetError(AsyncSocketUDPState state)

        {

            if (NetError != null)

            {

                NetError(this, new AsyncSocketUDPEventArgs(state));

            }

        }

 

        /// <summary>

        /// 异常事件

        /// </summary>

        public event EventHandler<AsyncSocketUDPEventArgs> OtherException;

        /// <summary>

        /// 触发异常事件

        /// </summary>

        /// <param name="state"></param>

        private void RaiseOtherException(AsyncSocketUDPState state, string descrip)

        {

            if (OtherException != null)

            {

                OtherException(this, new AsyncSocketUDPEventArgs(descrip, state));

            }

        }

        private void RaiseOtherException(AsyncSocketUDPState state)

        {

            RaiseOtherException(state, "");

        }

        #endregion

 

        #region Close

        /// <summary>

        /// 关闭一个与客户端之间的会话

        /// </summary>

        /// <param name="state">需要关闭的客户端会话对象</param>

        public void Close(AsyncSocketUDPState state)

        {

            if (state != null)

            {

                //_clients.Remove(state);

                //_clientCount--;

                //TODO 触发关闭事件

            }

        }

        /// <summary>

        /// 关闭所有的客户端会话,与所有的客户端连接会断开

        /// </summary>

        public void CloseAllClient()

        {

            //foreach (AsyncUDPSocketState client in _clients)

            //{

            //    Close(client);

            //}

            //_clientCount = 0;

            //_clients.Clear();

        }

 

        #endregion

 

        #region 释放

        /// <summary>

        /// Performs application-defined tasks associated with freeing, 

        /// releasing, or resetting unmanaged resources.

        /// </summary>

        public void Dispose()

        {

            Dispose(true);

            GC.SuppressFinalize(this);

        }

 

        /// <summary>

        /// Releases unmanaged and - optionally - managed resources

        /// </summary>

        /// <param name="disposing"><c>true</c> to release 

        /// both managed and unmanaged resources; <c>false</c> 

        /// to release only unmanaged resources.</param>

        protected virtual void Dispose(bool disposing)

        {

            if (!this.disposed)

            {

                if (disposing)

                {

                    try

                    {

                        Stop();

                        if (_serverSock != null)

                        {

                            _serverSock = null;

                        }

                    }

                    catch (SocketException)

                    {

                        //TODO

                        RaiseOtherException(null);

                    }

                }

                disposed = true;

            }

        }

        #endregion

    }

}

会话封装类：

using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

using System.Net;

using System.Net.Sockets;

 

namespace NetFrame.Net.UDP.Sock.Asynchronous

{

    public class AsyncSocketUDPState

    {

        // 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 EndPoint remote = new IPEndPoint(IPAddress.Any, 0);

    }

}

Socket异步UDP服务器事件参数类：

using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

 

namespace NetFrame.Net.UDP.Sock.Asynchronous

{

    /// <summary>

    /// SOCKET 异步UDP 事件类

    /// </summary>

    public class AsyncSocketUDPEventArgs : EventArgs

    {

        /// <summary>

        /// 提示信息

        /// </summary>

        public string _msg;

 

        /// <summary>

        /// 客户端状态封装类

        /// </summary>

        public AsyncSocketUDPState _state;

 

        /// <summary>

        /// 是否已经处理过了

        /// </summary>

        public bool IsHandled { get; set; }

 

        public AsyncSocketUDPEventArgs(string msg)

        {

            this._msg = msg;

            IsHandled = false;

        }

        public AsyncSocketUDPEventArgs(AsyncSocketUDPState state)

        {

            this._state = state;

            IsHandled = false;

        }

        public AsyncSocketUDPEventArgs(string msg, AsyncSocketUDPState state)

        {

            this._msg = msg;

            this._state = state;

            IsHandled = false;

        }

    }

}