根据 HttpWebRequest 的执行位置获得不同的响应

Question

我在控制台应用程序、MVC 控制器和类库中执行代码时遇到一些奇怪的问题。在前两种情况下，我得到了我期望的响应（在本例中是一个 zip 文件），但是当我尝试执行类库中的代码（MVC 控制器中的依赖项）时，我在响应中得到了 302 HTTP 状态，并带有奇怪的内容重定向到错误页面。

因此，奇怪的是它可以在我的控制台测试应用程序和 MVC 控制器中工作，但不能作为我的 MVC 项目中的依赖项。在控制器中执行此代码与在类库中作为依赖项执行此代码有什么区别吗？

我检查了 Fiddler 中的请求和响应，但一切都是相同的，当然除了 ASP.NET SessionId、视图状态和响应内容。

var cookies = new CookieContainer();

var firstRequest = (HttpWebRequest)WebRequest.Create("UrlToAspx");
firstRequest.Method = "GET";
firstRequest.KeepAlive = false;
firstRequest.CookieContainer = cookies;
var firstResponse = firstRequest.GetResponse() as HttpWebResponse;
var responseReader = new StreamReader(firstResponse.GetResponseStream());
var responseData = responseReader.ReadToEnd();
responseReader.Close();

var viewstate = ExtractViewstate(responseData);
var eventvalidation = ExtractEventValidation(responseData);

var postData = string.Format("__LASTFOCUS=&__EVENTTARGET=&__EVENTARGUMENT=&__VIEWSTATE={0}&__EVENTVALIDATION={1}&ctl00%24main%24ResultFormatGroup={2}&ctl00%24main%24DropDownList1={3}&&ctl00%24main%24fromDate={4}&&ctl00%24main%24tomDate={5}&&ctl00%24main%24ImageButton1.x={6}&&ctl00%24main%24ImageButton1.y={7}", viewstate, eventvalidation, "optExport", "Transaktioner", "2011-01-01", "2011-08-17", "7", "15");

var data = Encoding.UTF8.GetBytes(postData);

var request = (HttpWebRequest)HttpWebRequest.Create("UrlToAspx");
request.Method = "POST";
request.Accept = "text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8";
request.Headers.Add("Accept-Encoding", "gzip, deflate");
request.Headers.Add("Accept-Language", "sv-SE");
request.Headers.Add("Accept-Charset: ISO-8859-1,utf-8;q=0.7,*;q=0.7");
request.Referer = "Referer";
request.UserAgent = "Mozilla/5.0 (compatible; MSIE 9.0; Windows NT 6.1; WOW64; Trident/5.0)";
request.ContentType = "application/x-www-form-urlencoded";
request.Host = "referer";
request.Headers.Add("Pragma", "no-cache");
request.CookieContainer = cookies;
request.KeepAlive = false;
request.ContentLength = data.Length;

var newStream = request.GetRequestStream();
newStream.Write(data, 0, data.Length);
newStream.Close();

var secondStream = new StreamReader(request.GetResponse().GetResponseStream());
var realResponseData = secondStream.ReadToEnd();

Answer 1

将主机标头更改为您尝试访问的域，而不是使用引用站点。