sockets - TCP监听器和套接字之间的区别

Question

据我所知，我可以同时使用 TCPListener 和 Socket 创建服务器，那么它们两者之间有什么区别？

套接字

private Socket MainSock;
MainSock = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
MainSock.Bind(new IPEndPoint(IPAddress.Any, port));
MainSock.Listen(500);
MainSock.BeginAccept(AcceptConnections, new Wrapper());

TCPListener

    Int32 port = 13000;
    IPAddress localAddr = IPAddress.Parse("127.0.0.1");
    TcpListener server = new TcpListener(localAddr, port);
    server.Start();

我真的很困惑。两者都是监听连接，那么它们有什么区别呢？

更新代码

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Net;
using System.Net.Sockets;
using System.Net.Security;
using System.Security.Authentication;
using System.Security.Cryptography.X509Certificates;
using System.IO;

public class Wrapper
{
    public byte[] buffer;
    public SslStream sslStream;
    public object connector;
}

public class Sock
{
    private Dictionary<string, byte> Connections;
    public event Action<Wrapper> AnnounceNewConnection;
    public event Action<Wrapper> AnnounceDisconnection;
    public event Action<byte[], Wrapper> AnnounceReceive;
    private Socket _sock;

    private X509Certificate certificate = X509Certificate.CreateFromCertFile("exportedcertificate.cer");

    public Sock(int port)
    {
        try
        {
            Connections = new Dictionary<string, byte>();
            _sock = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
            _sock.Bind(new IPEndPoint(IPAddress.Any, port));
            _sock.Listen(500);
            _sock.BeginAccept(AcceptConnections, new Wrapper());
        }
        catch (Exception e)
        {
            Console.WriteLine(e);
        }
    }

    private void AcceptConnections(IAsyncResult result)
    {
        Wrapper wr = (Wrapper)result.AsyncState;
        try
        {
            wr.sslStream = new SslStream(new NetworkStream(_sock.EndAccept(result), true));
            wr.sslStream.BeginAuthenticateAsServer(certificate, AcceptAuthenticate, wr);

            _sock.BeginAccept(AcceptConnections, new Wrapper());
        }
        catch (Exception e) { Console.WriteLine(e); }
    }

    private void AcceptAuthenticate(IAsyncResult result)
    {
        Wrapper wr = (Wrapper)result.AsyncState;
        try
        {
            wr.sslStream.EndAuthenticateAsServer(result);
            if (wr.sslStream.IsAuthenticated == true)
            {
                AnnounceNewConnection.Invoke(wr);
            }
        }
        catch (Exception e) { Console.WriteLine(e); }
    }

    private void ReceiveData(IAsyncResult result)
    {
        Wrapper wr = (Wrapper)result.AsyncState;
        try
        {
            AnnounceReceive.Invoke(wr.buffer, wr);
        }
        catch (Exception e) { Console.WriteLine(e); AnnounceDisconnection.Invoke(wr); }
    }
}

Answer 1

TcpListener 是一个方便的 TCP 通信包装器。这允许您使用 TcpClient 来接受连接——尽管您可以接受套接字而不是客户端来使用 Socket 而不是 TcpClient。您可以使用 Socket 做同样的事情；但是您必须处理一些 TCP 特定的问题(例如 SocketType.Stream、ProtocolType.Tcp)。 TCP 是一种基于流的协议(protocol)，TcpClient 通过使用 TcpClient.GetStream() 提供流让您进行流通信来识别这一点。 Socket 处于更高 不同的级别，需要支持许多不同的协议(protocol)，例如 UDP，这些协议(protocol)不是基于流的。

TcpClient.GetStream返回一个适合SslStream的NetworkStream对象；所以，它应该比直接使用 Socket 简单得多。 documentation for SslStream使用 TcpListener 和 TcpClient 进行 SSL 通信的详细信息。