具有多个客户端的异步套接字服务器

Question

我有一个无法解决的问题，因为我的 c# 知识不是很好。 我在网上找了一些代码，根据自己的需要进行了修改。

我的问题是，当我向客户端发送消息时，只有一个接收消息，然后下一条消息被另一个客户端接收，依此类推。 我想在不丢失任何数据的情况下向所有连接的客户端发送相同的消息。

服务器

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


public class AsynchIOServer
{
    static TcpListener tcpListener = new TcpListener(10);

    static void Listeners()
    {

        Socket socketForClient = tcpListener.AcceptSocket();
        if (socketForClient.Connected)
        {
            Console.WriteLine("Client:"+socketForClient.RemoteEndPoint+" now connected to server.");
            NetworkStream networkStream = new NetworkStream(socketForClient);
            System.IO.StreamWriter streamWriter =
            new System.IO.StreamWriter(networkStream);
            System.IO.StreamReader streamReader =
            new System.IO.StreamReader(networkStream);

            ////here we send message to client
            while (true){
                Console.WriteLine("type your message to be recieved by client:");
                string theString = Console.ReadLine();
                streamWriter.WriteLine(theString);
                ////Console.WriteLine(theString);
                streamWriter.Flush();
            }
            streamReader.Close();
            networkStream.Close();
            streamWriter.Close();

        }
        socketForClient.Close();
        Console.WriteLine("Press any key to exit from server program");
        Console.ReadKey();
    }

    public static void Main()
    {
        //TcpListener tcpListener = new TcpListener(10);
        tcpListener.Start();
        Console.WriteLine("************This is Server program************");
        Console.WriteLine("Hoe many clients are going to connect to this server?:");
        int numberOfClientsYouNeedToConnect =int.Parse( Console.ReadLine());
        for (int i = 0; i < numberOfClientsYouNeedToConnect; i++)
        {
            Thread newThread = new Thread(new ThreadStart(Listeners));
            newThread.Start();
        }
    }
}

客户：

using System;
using System.Net.Sockets;
using System.Threading;
public class Client
{
    static public void Main(string[] Args)
    {
        TcpClient socketForServer;
        try
        {
            socketForServer = new TcpClient("localHost", 10);
        }
        catch
        {
            Console.WriteLine(
            "Failed to connect to server at {0}:999", "localhost");
            return;
        }

        NetworkStream networkStream = socketForServer.GetStream();
        System.IO.StreamReader streamReader =
        new System.IO.StreamReader(networkStream);
        System.IO.StreamWriter streamWriter =
        new System.IO.StreamWriter(networkStream);
        Console.WriteLine("*******This is client program who is connected to localhost on port No:10*****");

            try
            {
                string outputString;
            // read the data from the host and display it
            {
                while (true)
                {
                    outputString = streamReader.ReadLine();
                    Console.WriteLine("Message Recieved by server:" + outputString);

                    streamWriter.Flush();
                }
            }
        }
            catch
            {
                Console.WriteLine("Exception reading from Server");
            }
        // tidy up
        networkStream.Close();
        Console.WriteLine("Press any key to exit from client program");
        Console.ReadKey();
    }

    private static string GetData()
    {
        //Ack from sql server
        return "ack";
    }
}

谢谢

Answer 1

简单的工作多线程服务器：

    static void Process(Socket client) {

        Console.WriteLine("Incoming connection from " + client.RemoteEndPoint);

        const int maxMessageSize = 1024;
        byte[] response;
        int received;

        while (true) {

            // Send message to the client:
            Console.Write("Server: ");
            client.Send(Encoding.ASCII.GetBytes(Console.ReadLine()));
            Console.WriteLine();

            // Receive message from the server:
            response = new byte[maxMessageSize];
            received = client.Receive(response);
            if (received == 0) {
                Console.WriteLine("Client closed connection!");
                return;
            }

            List<byte> respBytesList = new List<byte>(response);
            respBytesList.RemoveRange(received, maxMessageSize - received); // truncate zero end
            Console.WriteLine("Client (" + client.RemoteEndPoint + "+: " + Encoding.ASCII.GetString(respBytesList.ToArray()));
        }
    }

    static void Main(string[] args) {

        int backlog = -1, port = 2222;

        Socket server = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
        server.ReceiveTimeout = -1;

        // Start listening.
        try {
            server.Bind(new IPEndPoint(IPAddress.Any, port));
            server.Listen(backlog);
        }
        catch (Exception) {
            Console.WriteLine("Listening failed!");
            Console.ReadKey();
            return;
        }

        Console.WriteLine("Start listening...");

        while(true) {
            Socket client = server.Accept();
            new System.Threading.Thread(() => {
                try { Process(client); } catch (Exception ex) { Console.WriteLine("Client connection processing error: " + ex.Message); }
            }).Start();
        }

        //Console.WriteLine("Press any key for exit...");
        //Console.ReadKey();
    }

和客户：

    static void WorkWithServer(Socket server) {

        const int maxMessageSize = 1024;
        byte[] response;
        int received;

        while(true) {

            try {

                // Receive message from the server:
                response = new byte[maxMessageSize];
                received = server.Receive(response);
                if (received == 0) {
                    Console.WriteLine("Server closed connection.");
                    return;
                }

                List<byte> respBytesList = new List<byte>(response);
                respBytesList.RemoveRange(received, maxMessageSize - received); // truncate zero end
                Console.WriteLine("Server: " + Encoding.ASCII.GetString(respBytesList.ToArray()));

                // Send message to the server:
                Console.Write("You: ");
                server.Send(Encoding.ASCII.GetBytes(Console.ReadLine()));
                Console.WriteLine();
            }
            catch (Exception ex) {
                Console.WriteLine("Error: " + ex.Message);
                return;
            }
        }

    }

    static void Main(string[] args) {

        IPEndPoint serverEp = new IPEndPoint(IPAddress.Parse("192.168.1.2"), 2222);

        Socket server = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
        server.ReceiveTimeout = -1;

        // Connect to the server.
        try { server.Connect(serverEp); }
        catch (Exception) {
            Console.WriteLine("Establish connection with server (" + serverEp + ") failed!");
            Console.ReadKey();
            return;
        }

        Console.WriteLine("Connection with server (" + serverEp + ") established!");
        WorkWithServer(server);

        Console.WriteLine("Press any key for exit...");
        Console.ReadKey();
    }

根据需要进行编辑。

Answer 2

你的代码错了。

首先，我将让您了解它的错误之处以及为什么它没有按您想要的方式工作。

您正在创建 n 个线程，并让它们都等待连接。如果你用尽了线程数怎么办？如果其中任何一个意外退出怎么办？

您也发送了错误的数据。通过使用Console.ReadLine，您不会通过多个线程传递数据并读取每个线程中的行，而是第一个调用 Console.ReadLine 的线程将接收它。这意味着您只会发送到一个 Socket。

您的管理方式并不理想。网上有几十个（如果不是几百个）多线程套接字服务器/客户端可用，我会邀请您进行更多研究。但首先，我希望您更多地研究 C# 中的线程/任务。