[C#]手把手教你打造Socket的TCP通讯连接（三）

上一篇中，我们编写了SocketHandler处理Socket的IO。

现在我们只剩下服务器端了。

服务器端包含两个类，一个TCPListener，一个TCPListenerClient。

TCPListener只管Start与Stop还有Accept。

TCPListenerClient是连接到服务器的客户端，相当于TCPClient在TCPListener上的体现。

现在我们开始编写TCPListener。

/// <summary>
/// TCP监听端
/// </summary>
public class TCPListener : IEnumerable<TCPListenerClient>
{
    private Socket socket;
    private HashSet<TCPListenerClient> clients;

    /// <summary>
    /// 实例化TCP监听者。
    /// </summary>
    public TCPListener()
    {
        clients = new HashSet<TCPListenerClient>();
        IsStarted = false;
        Handler = new SocketHandler();
    }

    public ISocketHandler Handler { get; set; }

    private int port;
    /// <summary>
    /// 监听端口。
    /// </summary>
    public int Port
    {
        get { return port; }
        set
        {
            if (value < 0 || value > 65535)
                throw new ArgumentOutOfRangeException(value + "不是有效端口。");
            port = value;
        }
    }

    /// <summary>
    /// 服务启动中
    /// </summary>
    public bool IsStarted { get; private set; }

    /// <summary>
    /// 开始服务。
    /// </summary>
    public void Start()
    {

    }

    /// <summary>
    /// 停止服务。
    /// </summary>
    public void Stop()
    {

    }

    /// <summary>
    /// 接收完成时引发事件。
    /// </summary>
    public event EventHandler<SocketEventArgs> ReceiveCompleted;
    /// <summary>
    /// 接受客户完成时引发事件。
    /// </summary>
    public event EventHandler<SocketEventArgs> AcceptCompleted;
    /// <summary>
    /// 客户断开完成时引发事件。
    /// </summary>
    public event EventHandler<SocketEventArgs> DisconnectCompleted;
    /// <summary>
    /// 发送完成时引发事件。
    /// </summary>
    public event EventHandler<SocketEventArgs> SendCompleted;

    /// <summary>
    /// 获取客户端泛型。
    /// </summary>
    /// <returns></returns>
    public IEnumerator<TCPListenerClient> GetEnumerator()
    {
        return clients.GetEnumerator();
    }

    /// <summary>
    /// 获取客户端泛型。
    /// </summary>
    /// <returns></returns>
    System.Collections.IEnumerator System.Collections.IEnumerable.GetEnumerator()
    {
        return clients.GetEnumerator();
    }

    /// <summary>
    /// 释放资源。
    /// </summary>
    /// <returns></returns>
    public void Dispose()
    {

    }
}

TCPListener继承IEnumerable<TCPListenerClient>与IDisposable

clients保存所有已连接的客户端。

编写Start方法。

    /// <summary>
    /// 开始服务。
    /// </summary>
    public void Start()
    {
        lock (this)
        {
            if (IsStarted)
                throw new InvalidOperationException("已经开始服务。");
            socket = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
            //绑定端口
            //可以引发端口被占用异常
            socket.Bind(new IPEndPoint(IPAddress.Any, port));
            //监听队列
            socket.Listen(512);
            //如果端口是0，则是随机端口，把这个端口赋值给port
            port = ((IPEndPoint)socket.LocalEndPoint).Port;
            //服务启动中设置为true
            IsStarted = true;
            //开始异步监听
            socket.BeginAccept(EndAccept, null);
        }
    }

    //异步监听结束
    private void EndAccept(IAsyncResult result)
    {
        //获得客户端Socket
        Socket clientSocket = socket.EndAccept(result);
        //实例化客户端类
        TCPListenerClient client = new TCPListenerClient(this, clientSocket);
        //增加事件钩子
        client.SendCompleted += client_SendCompleted;
        client.ReceiveCompleted += client_ReceiveCompleted;
        client.DisconnectCompleted += client_DisconnectCompleted;
        socket.BeginAccept(EndAccept, null);

        //增加客户端
        lock (clients)
            clients.Add(client);

        //客户端连接事件
        if (AcceptCompleted != null)
            AcceptCompleted(this, new SocketEventArgs(client, SocketAsyncOperation.Accept));
    }

    //客户端断开连接
    private void client_DisconnectCompleted(object sender, SocketEventArgs e)
    {
        //移除客户端
        lock (clients)
            clients.Remove((TCPListenerClient)e.Socket);

        e.Socket.DisconnectCompleted -= client_DisconnectCompleted;
        e.Socket.ReceiveCompleted -= client_ReceiveCompleted;
        e.Socket.SendCompleted -= client_SendCompleted;
        if (DisconnectCompleted != null)
            DisconnectCompleted(this, e);
    }

    //收到客户端发送的数据
    private void client_ReceiveCompleted(object sender, SocketEventArgs e)
    {
        if (ReceiveCompleted != null)
            ReceiveCompleted(this, e);
    }

    //向客户端发送数据完成
    private void client_SendCompleted(object sender, SocketEventArgs e)
    {
        if (SendCompleted != null)
            SendCompleted(this, e);
    }

编写Stop与Dispose方法。

    /// <summary>
    /// 停止服务。
    /// </summary>
    public void Stop()
    {
        lock (this)
        {
            if (!IsStarted)
                throw new InvalidOperationException("没有开始服务。");
            foreach (TCPListenerClient client in clients)
            {
                client.Disconnect();
                client.DisconnectCompleted -= client_DisconnectCompleted;
                client.ReceiveCompleted -= client_ReceiveCompleted;
                client.SendCompleted -= client_SendCompleted;
            }
            socket.Close();
            socket = null;
            IsStarted = false;
        }
    }

    /// <summary>
    /// 释放资源
    /// </summary>
    public void Dispose()
    {
        if (socket == null)
            return;
        Stop();
    }

轮到TCPListenerClient了，TCPListenerClient其实和TCPClient差不多，也是要继承ISocket和IDisposable。

既然重复代码做么多，要不要合并起来呢？答案是肯定的。

做一个SocketBase类，继承ISocket和IDisposable。

大部分代码直接从TCPClient复制过来。

public class SocketBase : ISocket, IDisposable
{
    protected Socket Socket { get; private set; }
    protected Stream Stream { get; set; }

    /// <summary>
    /// 实例化TCP客户端。
    /// </summary>
    public SocketBase(Socket socket, ISocketHandler socketHandler)
    {
        if (socket == null)
            throw new ArgumentNullException("socket");
        if (socketHandler == null)
            throw new ArgumentNullException("socketHandler");
        Socket = socket;
        Handler = socketHandler;
    }
    
    /// <summary>
    /// Socket处理程序
    /// </summary>
    public ISocketHandler Handler { get; set; }

    /// <summary>
    /// 获取是否已连接。
    /// </summary>
    public bool IsConnected { get { return Socket.Connected; } }

    #region 断开连接

    /// <summary>
    /// 断开与服务器的连接。
    /// </summary>
    public void Disconnect()
    {
        //判断是否已连接
        if (!IsConnected)
            throw new SocketException(10057);
        lock (this)
        {
            //Socket异步断开并等待完成
            Socket.BeginDisconnect(true, EndDisconnect, true).AsyncWaitHandle.WaitOne();
        }
    }

    /// <summary>
    /// 异步断开与服务器的连接。
    /// </summary>
    public void DisconnectAsync()
    {
        //判断是否已连接
        if (!IsConnected)
            throw new SocketException(10057);
        lock (this)
        {
            //Socket异步断开
            Socket.BeginDisconnect(true, EndDisconnect, false);
        }
    }

    private void EndDisconnect(IAsyncResult result)
    {
        try
        {
            Socket.EndDisconnect(result);
        }
        catch
        {

        }
        //是否同步
        bool sync = (bool)result.AsyncState;

        if (!sync && DisconnectCompleted != null)
        {
            DisconnectCompleted(this, new SocketEventArgs(this, SocketAsyncOperation.Disconnect));
        }
    }

    //这是一个给收发异常准备的断开引发事件方法
    private void Disconnected(bool raiseEvent)
    {
        if (raiseEvent && DisconnectCompleted != null)
            DisconnectCompleted(this, new SocketEventArgs(this, SocketAsyncOperation.Disconnect));
    }

    #endregion

    #region 发送数据

    /// <summary>
    /// 发送数据。
    /// </summary>
    /// <param name="data">要发送的数据。</param>
    public void Send(byte[] data)
    {
        //是否已连接
        if (!IsConnected)
            throw new SocketException(10057);
        //发送的数据不能为null
        if (data == null)
            throw new ArgumentNullException("data");
        //发送的数据长度不能为0
        if (data.Length == 0)
            throw new ArgumentException("data的长度不能为0");

        //设置异步状态
        SocketAsyncState state = new SocketAsyncState();
        state.IsAsync = false;
        state.Data = data;
        try
        {
            //开始发送数据
            Handler.BeginSend(data, 0, data.Length, Stream, EndSend, state).AsyncWaitHandle.WaitOne();
        }
        catch
        {
            //出现异常则断开Socket连接
            Disconnected(true);
        }
    }

    /// <summary>
    /// 异步发送数据。
    /// </summary>
    /// <param name="data">要发送的数据。</param>
    public void SendAsync(byte[] data)
    {
        //是否已连接
        if (!IsConnected)
            throw new SocketException(10057);
        //发送的数据不能为null
        if (data == null)
            throw new ArgumentNullException("data");
        //发送的数据长度不能为0
        if (data.Length == 0)
            throw new ArgumentException("data的长度不能为0");

        //设置异步状态
        SocketAsyncState state = new SocketAsyncState();
        state.IsAsync = true;
        state.Data = data;
        try
        {
            //开始发送数据并等待完成
            Handler.BeginSend(data, 0, data.Length, Stream, EndSend, state);
        }
        catch
        {
            //出现异常则断开Socket连接
            Disconnected(true);
        }
    }

    private void EndSend(IAsyncResult result)
    {
        SocketAsyncState state = (SocketAsyncState)result.AsyncState;

        //是否完成
        state.Completed = Handler.EndSend(result);
        //没有完成则断开Socket连接
        if (!state.Completed)
            Disconnected(true);
        //引发发送结束事件
        if (state.IsAsync && SendCompleted != null)
        {
            SendCompleted(this, new SocketEventArgs(this, SocketAsyncOperation.Send) { Data = state.Data });
        }
    }

    #endregion

    #region 接收数据

    protected void EndReceive(IAsyncResult result)
    {
        SocketAsyncState state = (SocketAsyncState)result.AsyncState;
        //接收到的数据
        byte[] data = Handler.EndReceive(result);
        //如果数据长度为0，则断开Socket连接
        if (data.Length == 0)
        {
            Disconnected(true);
            return;
        }

        //再次开始接收数据
        Handler.BeginReceive(Stream, EndReceive, state);

        //引发接收完成事件
        if (ReceiveCompleted != null)
            ReceiveCompleted(this, new SocketEventArgs(this, SocketAsyncOperation.Receive) { Data = data });
    }

    #endregion

    #region 事件

    ///// <summary>
    ///// 断开完成时引发事件。
    ///// </summary>
    public event EventHandler<SocketEventArgs> DisconnectCompleted;
    ///// <summary>
    ///// 接收完成时引发事件。
    ///// </summary>
    public event EventHandler<SocketEventArgs> ReceiveCompleted;
    ///// <summary>
    ///// 发送完成时引发事件。
    ///// </summary>
    public event EventHandler<SocketEventArgs> SendCompleted;

    #endregion

    /// <summary>
    /// 释放资源
    /// </summary>
    public void Dispose()
    {
        lock (this)
        {
            if (IsConnected)
                Socket.Disconnect(false);
            Socket.Close();
        }
    }
}

然后我们再写TCPListenerClient，继承SocketBase。

public class TCPListenerClient : SocketBase
{
    internal TCPListenerClient(TCPListener listener, Socket socket)
        :base(socket,listener.Handler)
    {
        data = new Dictionary<string, object>();
        this["RemoteEndPoint"] = socket.RemoteEndPoint;
        //创建Socket网络流
        Stream = new NetworkStream(socket);
//设置服务器
        Listener = listener;            //开始异步接收数据
        SocketAsyncState state = new SocketAsyncState();
        Handler.BeginReceive(Stream, EndReceive, state);
    }

    public TCPListener Listener { get; private set; }
}

我们还可以给TCPListenerClient加上点东西，比如类似Session的东西。

    private Dictionary<string, object> data;

    public object this[string key]
    {
        get
        {
            key = key.ToLower();
            if (data.ContainsKey(key))
                return data[key];
            return null;
        }
        set
        {

            key = key.ToLower();
            if (value == null)
            {
                if (data.ContainsKey(key))
                    data.Remove(key);
                return;
            }
            if (data.ContainsKey(key))
                data[key] = value;
            else
                data.Add(key, value);
        }
    }

为构造函数添加以下代码。

        data = new Dictionary<string, object>();
        //保存IP地址到字典
        this["RemoteEndPoint"] = socket.RemoteEndPoint;

这样，我们的TCPListenerClient就完成了。

接下来我们再把TCPClient修改以下，继承SocketBase。

/// <summary>
/// TCP客户端
/// </summary>
public class TCPClient : SocketBase
{
    /// <summary>
    /// 实例化TCP客户端。
    /// </summary>
    public TCPClient()
        : base(new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp), new SocketHandler())
    {
    }

    public bool IsUseAuthenticate { get; set; }

    /// <summary>
    /// 连接至服务器。
    /// </summary>
    /// <param name="endpoint">服务器终结点。</param>
    public void Connect(IPEndPoint endpoint)
    {
        //判断是否已连接
        if (IsConnected)
            throw new InvalidOperationException("已连接至服务器。");
        if (endpoint == null)
            throw new ArgumentNullException("endpoint");
        //锁定自己，避免多线程同时操作
        lock (this)
        {
            SocketAsyncState state = new SocketAsyncState();
            //Socket异步连接
            Socket.BeginConnect(endpoint, EndConnect, state).AsyncWaitHandle.WaitOne();
            //等待异步全部处理完成
            while (!state.Completed) { }
        }
    }

    /// <summary>
    /// 异步连接至服务器。
    /// </summary>
    /// <param name="endpoint"></param>
    public void ConnectAsync(IPEndPoint endpoint)
    {
        //判断是否已连接
        if (IsConnected)
            throw new InvalidOperationException("已连接至服务器。");
        if (endpoint == null)
            throw new ArgumentNullException("endpoint");
        //锁定自己，避免多线程同时操作
        lock (this)
        {
            SocketAsyncState state = new SocketAsyncState();
            //设置状态为异步
            state.IsAsync = true;
            //Socket异步连接
            Socket.BeginConnect(endpoint, EndConnect, state);
        }
    }

    private void EndConnect(IAsyncResult result)
    {
        SocketAsyncState state = (SocketAsyncState)result.AsyncState;

        try
        {
            Socket.EndConnect(result);
        }
        catch
        {
            //出现异常，连接失败。
            state.Completed = true;
            //判断是否为异步，异步则引发事件
            if (state.IsAsync && ConnectCompleted != null)
                ConnectCompleted(this, new SocketEventArgs(this, SocketAsyncOperation.Connect));
            return;
        }

        //连接成功。
        //创建Socket网络流
        Stream = new NetworkStream(Socket);
        if (IsUseAuthenticate)
        {
            NegotiateStream negotiate = new NegotiateStream(Stream);
            negotiate.AuthenticateAsClient();
            while (!negotiate.IsMutuallyAuthenticated)
            {
                Thread.Sleep(10);
            }
        }
        //连接完成
        state.Completed = true;
        if (state.IsAsync && ConnectCompleted != null)
        {
            ConnectCompleted(this, new SocketEventArgs(this, SocketAsyncOperation.Connect));
        }

        //开始接收数据
        Handler.BeginReceive(Stream, EndReceive, state);
    }

    /// <summary>
    /// 连接完成时引发事件。
    /// </summary>
    public event EventHandler<SocketEventArgs> ConnectCompleted;
}

所有工作，全部完成。

这个Socket还有很多功能可以增加、改造。

比如你自己写一个Handler内置加密解密，或者压缩与解压缩。

还可以再改写一下Stream，可以弄成NegotiateStream验证等等。

下一篇我们总结一下所有工作。

原文地址：http://www.cnblogs.com/Kation/archive/2013/03/07/2947278.html