Question

我正在使用套接字进行TCP-IP连接，我想从客户端建立简单的系统发送 - 接收。

 Socket sck;
        sck = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
        IPEndPoint localEndpt = new IPEndPoint(IPAddress.Parse("123.123.123.1"), 12345);
        try
        {
            sck.Connect(localEndpt);
        }
        catch
        {
            Console.Write("Unable to Connect");
        }
        while (true)
        {
            Console.WriteLine("Enter Text");
            string sendtext = Console.ReadLine();
            byte[] Data = Encoding.ASCII.GetBytes(sendtext);
            sck.Send(Data);
            Console.WriteLine("Data Sent!");

            byte[] bytesReceived = new byte[sck.ReceiveBufferSize];
            int bytes = 0;
            String strReceived = "";

            int dataAvailable = 0;
            while (dataAvailable == 0 || dataAvailable != sck.Available)
            {
                dataAvailable = sck.Available;
                Thread.Sleep(100); // if no new data after 100ms assume transmission finished
            }

            if (sck.Available > 0)
            {
                bytes = sck.Receive(bytesReceived, bytesReceived.Length, 0);
                strReceived+=Encoding.ASCII.GetString(bytesReceived, 0, bytes);
            }

            Console.WriteLine("Received from server: " + strReceived);
        }
        Console.Read();

问题在于第一个请求是通过，但第二个请求没有，因为套接字不再可用（套接字＆＃34;可用＆＃34;属性值为0）。我究竟做错了什么？建立多个发送 - 接收请求（按顺序）最简单的方法是什么？

Answer 1

Thread.Sleep NOT 指示套接字是否可用，但是传入的数据可供阅读：
Liskov Substitution Principle

您的程序退出是因为它在发送消息后立即检查回复（传入数据）。在检查数据之前使用Socket.Send。

可能还没有发送消息，因为{{1}}只是将它放在网络接口卡的输出缓冲区中。当套接字最终发送消息时，它将升级连接状态。如果没有回复（在TCP连接上），它将告诉您在查询状态时它已断开连接。在UDP上它不会告诉你什么，因为UDP是无连接的。

Answer 2

此代码适用于我

let a = 'object string';let jsObj = JSON.parse(a);console.log(jsObj);

只需运行此代码即可开始使用

    private List<Socket> _clients = new List<Socket>();
    private Thread _dataReceiveThread;
    private bool _isConnected;

    private void DataReceive()
    {
        while (_isConnected)
        {
            List<Socket> clients = new List<Socket>(_clients);
            foreach (Socket client in clients)
            {
                try
                {
                    if (!client.Connected) continue;
                    string txt = "";
                    while (client.Available > 0)
                    {
                        byte[] bytes = new byte[client.ReceiveBufferSize];
                        int byteRec = client.Receive(bytes);
                        if (byteRec > 0)
                            txt += Encoding.UTF8.GetString(bytes, 0, byteRec);
                    }
                    if (!string.IsNullOrEmpty(txt))
                        /* TODO: access the text received with "txt" */
                }
                catch (Exception e)
                {
                    Exception_Handler(e);
                }
            }
        }
    }

更新_isConnected = true; _dataReceiveThread = new Thread(DataReceive); _dataReceiveThread.Start(); 中的列表框：

此代码可以放在评论部分。

Cross thread

C＃客户端套接字多次发送和接收

2 个答案: