如何处理 TCP C# 套接字服务器中的多个活动连接？

Question

到目前为止，我的套接字服务器非常简单：

        public static void listen()
    {
        TcpListener server = null;
        IPAddress address = IPAddress.Parse("127.0.0.1");
        try
        {
            server = TcpListener.Create(5683);
            server.Start();

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


        while (true)
        {
            Thread.Sleep(10);
            TcpClient client = server.AcceptTcpClient();
            Console.WriteLine("Accepted Client");

            Thread thread = new Thread (new ParameterizedThreadStart(SwordsServer.ClientHandler));
            thread.IsBackground = true;
            thread.Start(client);
        }
    }

    public static void ClientHandler(object c)
    {
        TcpClient client = (TcpClient)c;
        NetworkStream netstream = client.GetStream();
        bool connected = true;
        while (connected)
        {
            Thread.Sleep(10);
            try
            {
                byte[] bytes = new byte[client.ReceiveBufferSize];                   
                netstream.Read(bytes, 0, bytes.Length);
                Console.WriteLine("got data");
                netstream.Write(bytes, 0, bytes.Length);

            }
            catch (Exception e)
            {
                connected = false;
                Console.WriteLine(e);
                Console.WriteLine(e.StackTrace);
            }
        }
    }

我的问题是，在概念层面上，您将如何关注每个唯一的 client 并将来自其他线程的更新发送到特定客户端？

例如，如果我有特定客户的数据，我如何联系该客户而不是广播它？或者，如果客户端不再连接，我怎么知道？

提前感谢您的帮助！

Answer 1

您接受多个连接的实现会创建匿名客户端，这意味着在超过 1 个连接之后您将无法识别正确的客户端。如果识别是问题，那么您可以做一件事，让客户端向服务器发送一个标识符，如“Client1”。创建一个 Dictionary 并在您的方法 ClientHandler() 中，从客户端读取标识符并将 TCPClient 的对象添加到字典中。

所以修改后的代码是这样的：

 Dictionary<string, TCPClient> dictionary = new Dictionary<string, TCPClient>();


 public static void ClientHandler(object c)
    {
        TcpClient client = (TcpClient)c;
        NetworkStream netstream = client.GetStream();
        bool connected = true;
        while (connected)
        {
            Thread.Sleep(10);
            try
            {
                byte[] bytes = new byte[client.ReceiveBufferSize];

                //read the identifier from client
                netstream.Read(bytes, 0, bytes.Length);

                String id = System.Text.Encoding.UTF8.GetString(bytes);

                //add the entry in the dictionary
                dictionary.Add(id, client);
                Console.WriteLine("got data");
                netstream.Write(bytes, 0, bytes.Length);

            }
            catch (Exception e)
            {
                connected = false;
                Console.WriteLine(e);
                Console.WriteLine(e.StackTrace);
            }
        }
    }

请注意：您的应用程序应该足够智能，可以动态决定更新应该发送到哪个客户端。