C# - 连接:在 HttpWebRequest 期间未发送保持活动标头 [英] C# - Connection: keep-alive Header is Not Being Sent During HttpWebRequest

问题描述

我正在尝试使用 HttpWebRequest 发送以下标头:

I'm trying to send to send the following header with my HttpWebRequest:

连接:保持活动

但是，标头永远不会发送.Fiddler2 显示每当我在 Google Chrome 中请求页面时，都会发送标头.但是，我的应用程序出于某种原因拒绝发送此标头.

However, the header is never sent. Fiddler2 is showing that whenever I request the page in Google Chrome, the header is sent. However, my application refuses to send this header for some reason.

我已将 KeepAlive 属性设置为 true(无论如何默认为 true)，但标头仍未发送.

I have set the KeepAlive property to true (it's true by default anyway), yet the header still does not get sent.

我试图用多个 HttpWebRequests 发送这个标头，但它们基本上都是这样的:

I am trying to send this header with multiple HttpWebRequests, but they all basically look like this:

HttpWebRequest logIn6 = (HttpWebRequest)WebRequest.Create(new Uri(responseFromLogIn5));
logIn6.CookieContainer = cookies;
logIn6.KeepAlive = true;
logIn6.Referer = "https://login.yahoo.com/config/login?.src=spt&.intl=us&.lang=en-US&.done=http://football.fantasysports.yahoo.com/";
logIn6.UserAgent = "Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/535.1 (KHTML, like Gecko) Chrome/13.0.782.220 Safari/535.1";
logIn6.Accept = "text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8";
logIn6.Headers.Add("Accept-Encoding:gzip,deflate,sdch");
logIn6.Headers.Add("Accept-Language:en-US,en;q=0.8");
logIn6.Headers.Add("Accept-Charset:ISO-8859-1,utf-8;q=0.7,*;q=0.3");
logIn6.AllowAutoRedirect = false;

HttpWebResponse logIn6Response = (HttpWebResponse)logIn6.GetResponse();
string responseFromLogIn6 = logIn6Response.GetResponseHeader("Location");

cookies.Add(logIn6Response.Cookies);

logIn6Response.Close();

有谁知道我必须做些什么才能确保发送此标头?

Does anyone know what I have to do to make sure this header is sent?

来自 Chrome 的 Fiddler2 Raw:

Fiddler2 Raw From Chrome:

GET xxx HTTP/1.1
Host: accounts.google.com
Connection: keep-alive
Referer: https://login.yahoo.com/config/login?.src=spt&.intl=us&.lang=en-US&.done=http://football.fantasysports.yahoo.com/
User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/535.1 (KHTML, like Gecko) Chrome/13.0.782.220 Safari/535.1
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8
Accept-Encoding: gzip,deflate,sdch
Accept-Language: en-US,en;q=0.8
Accept-Charset: ISO-8859-1,utf-8;q=0.7,*;q=0.3
Cookie: xxx

HTTP/1.1 302 Moved Temporarily
Set-Cookie: xxx
Set-Cookie: xxx
Location: xxx
Content-Type: text/html; charset=UTF-8
P3P: CP="This is not a P3P policy! See http://www.google.com/support/accounts/bin/answer.py?hl=en&answer=151657 for more info."
Date: Sat, 17 Sep 2011 22:27:09 GMT
Expires: Sat, 17 Sep 2011 22:27:09 GMT
Cache-Control: private, max-age=0
X-Content-Type-Options: nosniff
X-Frame-Options: SAMEORIGIN
X-XSS-Protection: 1; mode=block
Content-Length: 2176
Server: GSE

来自我的应用程序的 Fiddler2 Raw:

Fiddler2 Raw From My Application:

GET xxx HTTP/1.1
Referer: https://login.yahoo.com/config/login?.src=spt&.intl=us&.lang=en-US&.done=http://football.fantasysports.yahoo.com/
User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/535.1 (KHTML, like Gecko) Chrome/13.0.782.220 Safari/535.1
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8
Accept-Encoding: gzip,deflate,sdch
Accept-Language: en-US,en;q=0.8
Accept-Charset: ISO-8859-1,utf-8;q=0.7,*;q=0.3
Host: accounts.google.com

HTTP/1.1 302 Moved Temporarily
Location: xxx
Content-Type: text/html; charset=UTF-8
Date: Sun, 18 Sep 2011 00:05:40 GMT
Expires: Sun, 18 Sep 2011 00:05:40 GMT
Cache-Control: private, max-age=0
X-Content-Type-Options: nosniff
X-Frame-Options: SAMEORIGIN
X-XSS-Protection: 1; mode=block
Content-Length: 573
Server: GSE

我试图让第二个 Fiddler2 原始信息看起来像第一个 Fiddler2 原始信息.

I'm trying to get the second Fiddler2 raw information to look like the first Fiddler2 raw information.

推荐答案

我遇到了同样的问题:Connection: Keep-Alive 标头除了第一个请求之外没有发送，并且服务器如果丢失，我访问将不会给我正确的响应.所以，这里是我解决这个问题的方法:

I've had the same issue: The Connection: Keep-Alive header is not sent except the first request, and the server I accessed won't give me the correct response if it is missing. So, here are my workarounds to this issue:

首先将HttpWebRequest实例的ProtocolVersion属性设置为HttpVersion.Version10.除了 http 命令会变成 GET xxx HTTP/1.0 之外，它可以工作并且只使用公共 API.

First is set the ProtocolVersion property of HttpWebRequest instance to HttpVersion.Version10. Except the http command will become GET xxx HTTP/1.0, it works and uses only the public API.

第二种方式使用反射来修改HttpWebRequest实例的内部属性ServicePoint.HttpBehaviour，如下:

The second way uses the reflection to modify the internal property ServicePoint.HttpBehaviour of HttpWebRequest instance, like this:

var req = (HttpWebRequest)WebRequest.Create(someUrl);

var sp = req.ServicePoint;
var prop = sp.GetType().GetProperty("HttpBehaviour", 
                        BindingFlags.Instance | BindingFlags.NonPublic);
prop.SetValue(sp, (byte)0, null);

req.GetResponse().Close();

希望这会有所帮助.

这篇关于C# - 连接:在 HttpWebRequest 期间未发送保持活动标头的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！