c# - 根据执行 HttpWebRequest 的位置获得不同的响应

Question

我在控制台应用程序、MVC Controller 和类库中执行代码时遇到了一些奇怪的问题。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(依赖于我的 MVC Controller )时，我在响应中得到了 302 HTTP Status 和一个奇怪的重定向到错误页面。

所以奇怪的是它在我的控制台测试应用程序和 MVC Controller 中工作，但在我的 MVC 项目中不是作为依赖项。在 Controller 中执行此代码与作为依赖项在类库中执行此代码有什么不同吗？

我检查了 Fiddler 中的请求和响应，但除了 ASP.NET SessionId、viewstate 和响应内容之外，一切都是相同的。

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 header 更改为您尝试访问的域，而不是使用引荐来源网址。