C# 尝试使用httpwebrequest从SSL网站获取数据时超时？

长话短说，我正试图通过httpwebrequest访问，下面的代码在say或我们公司的网站上有效，但在Yahoo或Nasdaq上无效

这是带有注释的代码，因此它是自描述性的，提前谢谢

  // I've tried with tls12 or ssl3, still no luck
  System.Net.ServicePointManager.SecurityProtocol = SecurityProtocolType.Tls11;

  // "bumb" is just the variable storing the web address
  HttpWebRequest requestHtm = (HttpWebRequest)WebRequest.Create(bumb);

 // just in case...
 ServicePointManager.ServerCertificateValidationCallback = delegate { return 
 true; };


 //below follow a few lines trying to impersonate browser...just in case
   requestHtm.CookieContainer = new CookieContainer();
   requestHtm.AllowAutoRedirect = true;
   requestHtm.Accept = "text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8";
   requestHtm.Headers[HttpRequestHeader.AcceptEncoding] = "gzip, deflate";
   requestHtm.Headers[HttpRequestHeader.AcceptLanguage] = "en-gb,en;q=0.5";
   requestHtm.Headers[HttpRequestHeader.AcceptCharset] = "ISO-8859-1,utf-8;q=0.7,*;q=0.7";
   requestHtm.Timeout = 15000;
   requestHtm.UserAgent = "Mozilla/5.0 (Windows NT 6.1; WOW64; rv:2.0) Gecko/20100101 Firefox/4.0";
   requestHtm.Method = "GET"; 


// using "using" for simplicity...
using (HttpWebResponse responseHtm = (HttpWebResponse)requestHtm.GetResponse())
 {
                        StreamReader r = new StreamReader(responseHtm.GetResponseStream());

                        string text1 = r.ReadToEnd();

  //everything fails here: no messsage box gets shown, just timeout error 

                        MessageBox.Show(text1);

  } //closing the "using"

---

顺便说一句：这是针对4.5的，我正在win 8上测试，可能会在win 2012服务器上尝试，但需要它普遍工作…在4.0上，第一行不工作，但有办法替代Lambda exp。看起来，在任何框架版本上仍然没有运气。如果您将

15000

更改为

150000

，会发生什么情况？^现在将尝试它…显然我还需要等待更多：）@mjwills:看起来您是对的！我只是在雅虎上尝试了更长的超时时间，它工作正常……但是在纳斯达克，当我通过谷歌chrome打开它时，它只是不断地“旋转”……我指的是网站负载，但不是“完全”…aparently NET等待页面停止加载，但Nasdaq通过jscript或其他方式不断拉取实时数据，导致超时…这也是我的意思，但我的意思是，我甚至无法从chrome在Nasdaq上加载页面，因此它甚至可能是我的internet连接，ps-如果你可以添加它作为答案，以便我可以接受，10倍。

  /// button + textbox are added to the windows form, you also need to add  
  ///Using System.IO; Using System.Net; Using System.Net.Security at the very beginning...

 private void button1_Click(object sender, EventArgs e)
    {
        System.Net.ServicePointManager.SecurityProtocol = SecurityProtocolType.Tls12 | SecurityProtocolType.Ssl3 | SecurityProtocolType.Tls11;
              ServicePointManager.Expect100Continue = true;



              string bumb = "https://nasdaq.com";


                   HttpWebRequest requestHtm = (HttpWebRequest)WebRequest.Create(bumb);
                   ServicePointManager.ServerCertificateValidationCallback = delegate { return true; };



               //    requestHtm.CookieContainer = new CookieContainer();
                   requestHtm.AllowAutoRedirect = true;
                   requestHtm.KeepAlive = true;
               //    requestHtm.Accept = "text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8";
               //    requestHtm.Headers[HttpRequestHeader.AcceptEncoding] = "gzip, deflate";
               //    requestHtm.Headers[HttpRequestHeader.AcceptLanguage] = "en-gb,en;q=0.5";
               //    requestHtm.Headers[HttpRequestHeader.AcceptCharset] = "ISO-8859-1,utf-8;q=0.7,*;q=0.7";
                   requestHtm.Timeout = 150000;
                   //requestHtm.UserAgent = "Mozilla/5.0 (Windows NT 6.1; WOW64; rv:2.0) Gecko/20100101 Firefox/4.0";
                   requestHtm.UserAgent = "Mozilla/5.0 (Linux; Android 6.0; Nexus 5 Build/MRA58N) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/65.0.3325.181 Mobile Safari/537.36";

                 //requestHtm.Method = "GET"; 



                   using (HttpWebResponse responseHtm = (HttpWebResponse)requestHtm.GetResponse())
                   {
                       StreamReader r = new StreamReader(responseHtm.GetResponseStream());

                       string text1 = r.ReadToEnd();


                       textBox1.Text = text1;


                   }
    }