如何从套接字连续接收数据？

Question

我正在尝试通过 Windows 服务从套接字接收数据，但是当我建立连接时，它变得即时。我想不断地接收它（端口关闭时它会断开连接）。我怎样才能做到这一点？

这是我现在的输出；

"GET/HTTP/1.1

主机：127.0.0.1:1994

连接：保持活动

缓存控制：max-age=0

升级不安全请求：1

用户代理：Mozilla/5.0（Windows NT 10.0；Win64；x64）AppleWebKit/537.36（KHTML，如 Gecko）Chrome/51.0.2704.106 Safari/537.36

接受：text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,/;q=0.8

接受编码：gzip、deflate、sdch

接受语言：tr-TR,tr;q=0.8,en-US;q=0.6,en;q=0.4

连接继续？假”

using System;
using System.IO;
using System.Net;
using System.Text;
using System.Linq;
using System.Threading;
using System.Net.Sockets;
using System.Diagnostics;
using System.ComponentModel;
using System.ServiceProcess;
using System.Collections.Generic;

namespace AServiceTest
{
    public partial class Service1 : System.ServiceProcess.ServiceBase
    {
        Thread th;
        bool isRunning = false;
        byte[] bytes = new byte[1024];

        public Service1() 
        {
            InitializeComponent();
        }
        protected override void OnStart(string[] args)
        {
            th = new Thread(DoThis);
            th.Start();
            isRunning = true;            
        }
        private void DoThis()
        {
            while (isRunning)
            {
                    Socket listener, connecter, acc;
                    listener = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
                    connecter = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp); //Variables

                    listener.Bind(new IPEndPoint(IPAddress.Parse("127.0.0.1"), 1994));
                    listener.Listen(0);

                    acc = listener.Accept(); //Accepting comm with client part
                    bool IsConnected = !((listener.Poll(1000, SelectMode.SelectRead) && (listener.Available == 0)) || !listener.Connected);

                    File.AppendAllText(@"D:\Tasks\dataGathering.txt", Environment.NewLine + "Connection proceed?1 " + IsConnected);


                new Thread(() =>
                {

                    byte[] bytes = new byte[1024];
                    int byteCount = acc.Receive(bytes, SocketFlags.None);

                    File.AppendAllText(@"D:\Tasks\dataGathering.txt", Environment.NewLine + "Connection proceed?2 " + IsConnected);

                    Console.WriteLine(Encoding.UTF8.GetString(bytes)); //It encodes before writing to the screen
                    File.AppendAllText(@"D:\Tasks\dataGathering.txt", Environment.NewLine + " " + Encoding.UTF8.GetString(bytes));

                    File.AppendAllText(@"D:\Tasks\dataGathering.txt", Environment.NewLine + "Connection proceed?3 " + IsConnected);


                    File.AppendAllText(@"D:\Tasks\dataGathering.txt", Environment.NewLine + "Connection proceed? " + IsConnected);
                    Console.WriteLine("Does connection proceeding? " + IsConnected);

                }).Start();
            }
        }        
        protected override void OnStop() 
        {
            isRunning = false;
            th = null;
        }
        private void InitializeComponent() 
        {
            this.ServiceName = "AServiceTest";
            this.CanStop = true;
            this.AutoLog = false;
            this.EventLog.Log = "Application";
            this.EventLog.Source = "Service1";
        }
    }
}

Answer 1

要连续接收数据，您实际上需要放入一些循环。

例如：

private void StartProcessing(Socket serverSocket)
{
    var clientSocket = serverSocket.Accept();
    StartReceiveing(clientSocket);
}

private void StartReceiveing(Socket clientSocket)
{
    const int maxBufferSize = 1024;

    try
    {
        while (true)
        {
            var buffer = new byte[maxBufferSize];

            var bytesRead = clientSocket.Receive(buffer);

            if (ClientIsConnected(clientSocket))
            {
                var actualData = new byte[bytesRead];

                Array.Copy(buffer, actualData, bytesRead);
                OnDataReceived(actualData);
            }
            else
            {
                OnDisconnected(clientSocket);
            }
        }
    }
    catch (SocketException ex)
    {
        Console.WriteLine(ex.Message);
    }
}

private void OnDisconnected(Socket issuedSocket)
{
    if (issuedSocket != null)
    {
        issuedSocket.Shutdown(SocketShutdown.Both);
        issuedSocket.Close();

        StartProcessing(listener);
    }
}

private void OnDataReceived(byte[] data)
{
    //do cool things
}

private static bool ClientIsConnected(Socket socket)
{
    return !(socket.Poll(1000, SelectMode.SelectRead) && socket.Available == 0);
}

另外，就您而言，我考虑阅读有关 socket async API 以及有关任务和异步编程的信息。有了这些，你可以做一些很酷很干净的事情，比如：

await Task.Factory.FromAsync(serverSocket.BeginAccept, result => serverSocket.EndAccept(result), serverSocket);

哪个不会阻止您当前的Thread。