c# HTTP读写超时问题

Question

我正在玩HttpWebRequest类，对超时/读写超时成员感到困惑。问题是读写超时有时会被忽略，然后我的应用程序在我的GetResponse()呼叫上挂起5分钟。有时它只是抛出一个WebException，有时它挂起5分钟，这似乎是默认值。我甚至在调用GetResponse()之前检查读写超时值，它总是正确的值，我设置为10000。

var getPage = WebRequest.Create(url) as HttpWebRequest;
getPage.Accept = "text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8";
getPage.UserAgent = "Mozilla/5.0 (Windows; U; Windows NT 6.1; en-US; rv:1.9.2.19) Gecko/20110707 Firefox/3.6.19";
getPage.ProtocolVersion = HttpVersion.Version11;
getPage.Method = "GET";
getPage.CookieContainer = foo;
getPage.Proxy = proxyHTTP;
getPage.Timeout = 10000;
getPage.ReadWriteTimeout = 10000;

//在另一个函数中，我将getPage传递给

Console.WriteLine("Timeout: {0} / ReadWriteTimeout{1}", page.Timeout, page.ReadWriteTimeout);
var pageResponse = (HttpWebResponse)page.GetResponse();
Console.WriteLine("It reaches this line after 5 minutes");
if (pageResponse.StatusCode == HttpStatusCode.OK)
{
    // read and close it afterwards
}

我正在使用HTTP代理。奇怪的是，url在浏览器中加载得很好。如有任何意见，我将不胜感激。

//编辑

namespace Proxy
{
 class Program
 {
     static void Main(string[] args)
     {
        var htmlResponse = new StringBuilder();
        var RequestPage = BuildHttpRequest("https://twitter.com/signup");
        GetHttpResponse(RequestPage, htmlResponse);
    }
    public static HttpWebRequest BuildHttpRequest(string url)
    {
        try
        {
            var getPage = (HttpWebRequest)WebRequest.Create(url);
            WebProxy proxyHTTP = new WebProxy("201.38.194.50", 3128);

            getPage.Accept = "text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8";
            getPage.UserAgent = "Mozilla/5.0 (Windows; U; Windows NT 6.1; en-US; rv:1.9.2.19) Gecko/20110707 Firefox/3.6.19";
            getPage.ProtocolVersion = HttpVersion.Version11;
            getPage.Method = "GET";
            getPage.Proxy = proxyHTTP;
            getPage.Timeout = 10000;
            getPage.ReadWriteTimeout = 10000;
            return getPage;
        }
        catch (WebException ex)
        {
            Console.WriteLine(ex.ToString());
        }
        return null;
    }
    public static bool GetHttpResponse(HttpWebRequest page, StringBuilder html)
    {
        html.Clear();
        try
        {
            Console.WriteLine("A");
            var pageResponse = (HttpWebResponse)page.GetResponse();
            Console.WriteLine("5 minutes!");
            if (pageResponse.StatusCode == HttpStatusCode.OK)
            {
                var reader = new StreamReader(pageResponse.GetResponseStream());
                html.Append(reader.ReadToEnd());
                pageResponse.Close();
                reader.Close();
                return true;
            }
            Console.WriteLine(pageResponse.StatusCode.ToString());
            pageResponse.Close();
            return false;
        }
        catch (WebException ex)
        {
            Console.WriteLine(ex.ToString());
        }
        return false;
    }
}

}

    A first chance exception of type 'System.Net.WebException' occurred in System.dll
    System.Net.WebException: The operation has timed out
    at System.Net.HttpWebRequest.GetResponse()

Answer 1

你可以试试这个吗

    var request = (HttpWebRequest)WebRequest.Create(url);
    using (var pageResponse = request.GetResponse())
    {
       // Do stuff with `response` here 
    } 
// drop the as HttpWebRequest; 
// The response however is, these will eventually be reclaimed by the GC 
// but you'll run into problems similar to deadlocks if you don't dispose them yourself 
// when you have many of them