C# 中的套接字：如何获取响应流？

Sockets in C#: How to get the response stream?

提问by Matías

I'm trying to replace this:

我正在尝试替换这个：

void ProcessRequest(object listenerContext)
{
    var context = (HttpListenerContext)listenerContext;
    Uri URL = new Uri(context.Request.RawUrl);
    HttpWebRequest.DefaultWebProxy = null;
    HttpWebRequest httpWebRequest = (HttpWebRequest)WebRequest.Create(URL);
    httpWebRequest.Method = context.Request.HttpMethod;
    httpWebRequest.Headers.Clear();
    if (context.Request.UserAgent != null) httpWebRequest.UserAgent = context.Request.UserAgent;
    foreach (string headerKey in context.Request.Headers.AllKeys)
    {
        try { httpWebRequest.Headers.Set(headerKey, context.Request.Headers[headerKey]); }
            catch (Exception) { }
    }

    using (HttpWebResponse httpWebResponse = (HttpWebResponse)httpWebRequest.GetResponse())
    {
        Stream responseStream = httpWebResponse.GetResponseStream();
        if (httpWebResponse.ContentEncoding.ToLower().Contains("gzip"))
            responseStream = new GZipStream(responseStream, CompressionMode.Decompress);
        else if (httpWebResponse.ContentEncoding.ToLower().Contains("deflate"))
                responseStream = new DeflateStream(responseStream, CompressionMode.Decompress);

        MemoryStream memStream = new MemoryStream();

        byte[] respBuffer = new byte[4096];
        try
        {
            int bytesRead = responseStream.Read(respBuffer, 0, respBuffer.Length);
            while (bytesRead > 0)
            {
                memStream.Write(respBuffer, 0, bytesRead);
                bytesRead = responseStream.Read(respBuffer, 0, respBuffer.Length);
            }
        }
        finally
        {
            responseStream.Close();
        }

        byte[] msg = memStream.ToArray();

        context.Response.ContentLength64 = msg.Length;
        using (Stream strOut = context.Response.OutputStream)
        {
            strOut.Write(msg, 0, msg.Length);
        }
    }
    catch (Exception ex)
    {
        // Some error handling
    }
}

with sockets. This is what I have so far:

带插座。这是我到目前为止：

void ProcessRequest(object listenerContext)
{
    HttpListenerContext context = (HttpListenerContext)listenerContext;
    Uri URL = new Uri(context.Request.RawUrl);
    string getString = string.Format("GET {0} HTTP/1.1\r\nHost: {1}\r\nAccept-Encoding: gzip\r\n\r\n",
                context.Request.Url.PathAndQuery,
                context.Request.UserHostName);

    Socket socket = null;

    string[] hostAndPort;
    if (context.Request.UserHostName.Contains(":"))
    {
        hostAndPort = context.Request.UserHostName.Split(':');
    }
    else
    {
        hostAndPort = new string[] { context.Request.UserHostName, "80" };
    }

    IPHostEntry ipAddress = Dns.GetHostEntry(hostAndPort[0]);
    IPEndPoint ip = new IPEndPoint(IPAddress.Parse(ipAddress.AddressList[0].ToString()), int.Parse(hostAndPort[1]));
    socket = new Socket(ip.AddressFamily, SocketType.Stream, ProtocolType.Tcp);
    socket.Connect(ip);

BEGIN NEW CODE

开始新代码

Encoding ASCII = Encoding.ASCII;
Byte[] byteGetString = ASCII.GetBytes(getString);
Byte[] receiveByte = new Byte[256];
string response = string.Empty;
socket.Send(byteGetString, byteGetString.Length, 0);
Int32 bytes = socket.Receive(receiveByte, receiveByte.Length, 0);
response += ASCII.GetString(receiveByte, 0, bytes);
while (bytes > 0)
{
bytes = socket.Receive(receiveByte, receiveByte.Length, 0);
strPage = strPage + ASCII.GetString(receiveByte, 0, bytes);
}
socket.Close();

string separator = "\r\n\r\n";
string header = strPage.Substring(0,strPage.IndexOf(separator));
string content = strPage.Remove(0, strPage.IndexOf(separator) + 4);

byte[] byteResponse = ASCII.GetBytes(content);
context.Response.ContentLength64 = byteResponse .Length;
context.Response.OutputStream.Write(byteResponse , 0, byteResponse .Length);
context.Response.OutputStream.Close();

END NEW CODE

结束新代码

After connecting to the socket I don't know how to get the Stream response to decompress, and send back to context.Response.OutputStream

连接到套接字后，我不知道如何获取 Stream 响应进行解压缩，并将其发送回context.Response.OutputStream

Any help will be appreciated. Thanks. Cheers.

任何帮助将不胜感激。谢谢。干杯。

EDIT 2:With this edit now seems to be working fine (same as HttpWebRequest at least). Do you find any error here?

编辑 2：使用此编辑现在似乎工作正常（至少与 HttpWebRequest 相同）。你在这里发现任何错误吗？

EDIT 3:False alarm... Still can't get this working

编辑 3：误报...仍然无法正常工作

EDIT 4:I needed to add the following lines to Scott's code ... because not always the first to bytes of reponseStream are the gzip magic number. The sequence seems to be: 0x0a (10), 0x1f (31), 0x8b (139). The last two are the gzip magic number. The first number was always before in my tests.

编辑 4：我需要在 Scott 的代码中添加以下几行......因为并不总是 reponseStream 的第一个字节是 gzip 幻数。序列似乎是：0x0a (10), 0x1f (31), 0x8b (139)。最后两个是 gzip 幻数。在我的测试中，第一个数字总是在前面。

if (contentEncoding.Equals("gzip"))
{
    int magicNumber = 0;
    while (magicNumber != 10)
        magicNumber = responseStream.ReadByte();
    responseStream = new GZipStream(responseStream, CompressionMode.Decompress);
}

采纳答案by Scott

Here's some code that works for me.

这是一些对我有用的代码。

using System;
using System.Collections.Generic;
using System.IO;
using System.Net;
using System.Net.Sockets;
using System.Text;
using System.IO.Compression;

namespace HttpUsingSockets {
    public class Program {
        private static readonly Encoding DefaultEncoding = Encoding.ASCII;
        private static readonly byte[] LineTerminator = new byte[] { 13, 10 };

        public static void Main(string[] args) {
            var host = "stackoverflow.com";
            var url = "/questions/523930/sockets-in-c-how-to-get-the-response-stream";

            IPHostEntry ipAddress = Dns.GetHostEntry(host);
            var ip = new IPEndPoint(ipAddress.AddressList[0], 80);
            using (var socket = new Socket(ip.AddressFamily, SocketType.Stream, ProtocolType.Tcp)) {
                socket.Connect(ip);
                using (var n = new NetworkStream(socket)) {
                    SendRequest(n, new[] {"GET " + url + " HTTP/1.1", "Host: " + host, "Connection: Close", "Accept-Encoding: gzip"});

                    var headers = new Dictionary<string, string>();
                    while (true) {
                        var line = ReadLine(n);
                        if (line.Length == 0) {
                            break;
                        }
                        int index = line.IndexOf(':');
                        headers.Add(line.Substring(0, index), line.Substring(index + 2));
                    }

                    string contentEncoding;
                    if (headers.TryGetValue("Content-Encoding", out contentEncoding)) {
                        Stream responseStream = n;
                        if (contentEncoding.Equals("gzip")) {
                            responseStream = new GZipStream(responseStream, CompressionMode.Decompress);
                        }
                        else if (contentEncoding.Equals("deflate")) {
                            responseStream = new DeflateStream(responseStream, CompressionMode.Decompress);
                        }

                        var memStream = new MemoryStream();

                        var respBuffer = new byte[4096];
                        try {
                            int bytesRead = responseStream.Read(respBuffer, 0, respBuffer.Length);
                            while (bytesRead > 0) {
                                memStream.Write(respBuffer, 0, bytesRead);
                                bytesRead = responseStream.Read(respBuffer, 0, respBuffer.Length);
                            }
                        }
                        finally {
                            responseStream.Close();
                        }

                        var body = DefaultEncoding.GetString(memStream.ToArray());
                        Console.WriteLine(body);
                    }
                    else {
                        while (true) {
                            var line = ReadLine(n);
                            if (line == null) {
                                break;
                            }
                            Console.WriteLine(line);
                        }
                    }
                }
            }
        }

        static void SendRequest(Stream stream, IEnumerable<string> request) {
            foreach (var r in request) {
                var data = DefaultEncoding.GetBytes(r);
                stream.Write(data, 0, data.Length);
                stream.Write(LineTerminator, 0, 2);
            }
            stream.Write(LineTerminator, 0, 2);
            // Eat response
            var response = ReadLine(stream);
        }

        static string ReadLine(Stream stream) {
            var lineBuffer = new List<byte>();
            while (true) {
                int b = stream.ReadByte();
                if (b == -1) {
                    return null;
                }
                if (b == 10) {
                    break;
                }
                if (b != 13) {
                    lineBuffer.Add((byte)b);
                }
            }
            return DefaultEncoding.GetString(lineBuffer.ToArray());
        }
    }
}

You could substitute this for the Socket/NetworkStream and save a bit of work.

您可以将其替换为 Socket/NetworkStream 并节省一些工作。

using (var client = new TcpClient(host, 80)) {
      using (var n = client.GetStream()) {
     }
} 

回答by Mehrdad Afshari

Socket, by definition, is the low level to access the network. You can even use datagram protocols with a socket. In that case a stream does not make sense at all.

Socket，顾名思义，就是访问网络的底层。您甚至可以使用带有套接字的数据报协议。在这种情况下，流根本没有意义。

While I'm not sure why are you doing what HttpWebRequest easily accomplishes, to read/write data to a socket, you use the Send/Receive methods. If you want to have a stream like access to a TCP socket, you should use the TcpClient/TcpListener classes which wrap a socket and provide a network stream for it.

虽然我不确定您为什么要执行 HttpWebRequest 轻松完成的操作，但要将数据读/写到套接字，您可以使用 Send/Receive 方法。如果您想要像访问 TCP 套接字这样的流，您应该使用 TcpClient/TcpListener 类来包装套接字并为其提供网络流。

回答by David Anderson

There's also the NetworkStream class that takes a Socket as a parameter. ;)

还有将 Socket 作为参数的 NetworkStream 类。;)