如何在C＃中正确发送KeepAlive头文件？

问题描述：

我需要使用的HttpWebRequest发送这样的请求：如何在C＃中正确发送KeepAlive头文件？

POST https://sap.site.com.mx/sap/bw/BEx?SAP-LANGUAGE=ES&PAGENO=1&CMD=PROCESS_VARIABLES&REQUEST_NO=0&CMD=PROCESS_VARIABLES&SUBCMD=VAR_SUBMIT&VARID= HTTP/1.1 
User-Agent: Mozilla/5.0 (Windows NT 5.1; rv:10.0.2) Gecko/20100101 Firefox/10.0.2 
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8 
Accept-Language: es-MX,es;q=0.8,en-us;q=0.5,en;q=0.3 
Accept-Encoding: gzip, deflate 
Connection: keep-alive

但是，我不能发送连接头。这是我的代码：

// request 
HttpWebRequest request = CreateWebRequestObject(url); 
request.CookieContainer = this.cc; 
request.UserAgent = "Mozilla/5.0 (Windows NT 5.1; rv:10.0.2) Gecko/20100101 Firefox/10.0.2"; 

// headers 
request.Headers.Add("Accept-Encoding", "gzip, deflate"); 
request.Headers.Add("Accept-Language", " es-MX,es;q=0.8,en-us;q=0.5,en;q=0.3"); 
request.Accept = "text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8"; 
request.KeepAlive = true; // it does not work as expected 
request.ServicePoint.Expect100Continue = false; // remove Expect header 

// post 
request.Method = "POST"; 
request.ContentType = "application/x-www-form-urlencoded"; 
request.ContentLength = buffer.Length; 

using (Stream stream = request.GetRequestStream()) 
    stream.Write(buffer, 0, buffer.Length);

但是，当我检查Fiddler中的请求Connection属性不会出现。

此外，这些职位不适合我的工作：

Keep a http connection alive in C#?
C# - Connection: keep-alive Header is Not Being Sent During HttpWebRequest

如何正确地发送连接头？

UPDATE

这个附加保活使用HTTP/1.0

request.ProtocolVersion = HttpVersion.Version10; 
//request.KeepAlive = true; // not necessary

当变化ProtocolVersion属性HttpVersion.Version11，保持活动头没有被发送：

request.ProtocolVersion = HttpVersion.Version11; 
request.KeepAlive = true;

如何使用Http/1.1发送Keep-Alive头文件？

在http1.1中KeepAlive是默认的，不是？ – 2012-03-05 18:02:59

如果您使用ServicePointManager.Expect100Continue = false;顺便说一下，有同样的问题。它是一个.net错误吗？ – 2012-03-10 17:29:59

答

我有非常相似的代码相同的错误，并设置

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

DID解决它。你确定每次创建httpwebrequest时都确实执行了这段代码吗？

答

使用HTTP/1.1时，Keep-Alive默认为打开。将KeepAlive设置为false可能会导致向服务器发送Connection：Close标头。

如何在C＃中正确发送KeepAlive头文件？

相关推荐