我正在学习套接字,目前；我正在努力向所有连接的客户端广播消息.

服务器只是用以下代码启动：

public static int Main(String[] args)
{

    Thread t1 = new Thread(Test);
    t1.Start();


    #region Start listening to socket
    IPHostEntry ipHostInfo = Dns.GetHostEntry(Dns.GetHostName());
    IPAddress ipAddress = ipHostInfo.AddressList[0];
    IPEndPoint localEndPoint = new IPEndPoint(ipAddress,11000);

    Socket listener = new Socket(ipAddress.AddressFamily,SocketType.Stream,ProtocolType.Tcp);

    try
    {
        listener.Bind(localEndPoint);
        listener.Listen(100);

        Console.WriteLine("[{0}] Server started listening!",DateTime.Now);
        while (true)
        {
            // Set the event to nonsignaled state.  
            allDone.Reset();

            // Start an asynchronous socket to listen for connections.
            listener.BeginAccept(new AsyncCallback(AcceptCallback),listener);

            // Wait until a connection is made before continuing.  
            allDone.WaitOne();
        }
    }
    catch (Exception e)
    {
        Console.WriteLine(e.ToString());
    }
    #endregion

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

    return 0;
}

在那里,我启动套接字以侦听是否有人发送消息.

如您所见,我在那里建立了线程,并且希望该线程不时向所有连接的用户发送一些消息(目前所有时间仅几个字节用于测试).

这是线程中的方法

private static void Test()
{
    while (true)
    {
        for (int i = 0; i < Players.Length; i++)
        {
            if (Players[i] == null)
                continue;

            Socket cs = new Socket(Players[i].IPEndPoint.AddressFamily,ProtocolType.Tcp);

            cs.Bind(Players[i].IPEndPoint);

            byte[] data = Encoding.ASCII.GetBytes("Random data");

            cs.Send(data);
        }
    }
}

此方法仅是最后一次尝试,但未成功.问题是它使我发现以下错误：

socket is reference of null.

在这种情况下,但无论如何,我都无法将消息发送给每个客户端.

这是我跟踪客户端与服务器连接的方式.

case "0": // Client tries to connect to server

    if (nClients >= MAX_PLAYERS)
    {
        Send(handler,"Too many players. Try again later.");
        return;
    }

    for (int i = 0; i < MAX_PLAYERS; i++)
    {
        if(Players[i] == null)
        {
            Players[i] = new Client();
            Players[i].Name = parts[1].ToString();
            Players[i].IPEndPoint = handler.RemoteEndPoint as IPEndPoint;

            Send(handler,String.Format("1|{0}",i));
            Console.WriteLine("[{0}] Succesfully registered client ID: {1},NAME: {2}!",DateTime.Now,i,parts[1].ToString());
            i = MAX_PLAYERS;
            nClients++;
        }
    }
    break;

这只是专注于处理连接消息的代码的一部分,该消息位于我的方法内部：

private static void HandleMessages(string message,Socket handler)

我从这里调用它：

public static void AcceptCallback(IAsyncResult ar)
{
    // Signal the main thread to continue.  
    allDone.Set();

    // Get the socket that handles the client request.  
    Socket listener = (Socket)ar.AsyncState;
    Socket handler = listener.EndAccept(ar);

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

        // Check for end-of-file tag. If it is not there,read   
        // more data.  
        content = state.sb.ToString();
        if (content.IndexOf("<EOF>") > -1)
        {
            string message = content.Remove(content.Length - 5,5);
            HandleMessages(message,handler);
        }
        else
        {
            // Not all data received. Get more.  
            handler.BeginReceive(state.buffer,state);
        }
    }
}