c#之URL 在浏览器中有效，但无法从 Web 客户端或 Web 请求获得响应

我有一个关于服务器响应的问题。 (返回 403 禁止)。

当我在浏览器中检查相同的 url 时，我可以看到该页面。

我已经编写了以下代码来获取响应。

我在本地 PC 上执行相同的代码，它工作正常。

 HttpWebRequest request = WebRequest.Create(RequestUrl) as HttpWebRequest; 
                request.Method = "POST"; 
                request.CookieContainer = new CookieContainer(); 
                request.Timeout = 600000; 
                request.Accept = "*/*"; 
                request.UserAgent = "Mozilla/5.0 (Windows NT 6.1; rv:18.0) Gecko/20100101 Firefox/18.0"; 
 
WebResponse response; 
                try 
                { 
                    response = request.GetResponse(); 
                    string StatusDescription = ((HttpWebResponse)response).StatusDescription; 
 
                    if (StatusDescription.ToLower() == "ok") 
                    { 
                        Stream dataStream = response.GetResponseStream(); 
                        //XmlDocument XmlResponse = new XmlDocument(); 
                        //XmlResponse.Load(dataStream);             
                        //XmlResponse.Save(Server.MapPath("~/XMLResponse.xml")); 
                        StreamReader reader = new StreamReader(dataStream); 
                        string responseFromServer = reader.ReadToEnd(); 
                        responseFromServer = responseFromServer.Replace(" ", ""); 
                        responseFromServer = responseFromServer.Replace("&", "&"); 
                        reader.Close(); 
                        dataStream.Dispose(); 
                        response.Close(); 
                        responseFromServer = GetStringsBetweenTags(responseFromServer, "<head>", "</head>"); 
                        return responseFromServer; 
                    } 
                    else 
                    { 
                        //To Do : add code for notify error via email 
                    } 
                } 
                catch (Exception ex) 
                {                    
                    WebClient webclient = new WebClient(); 
                    using (StreamReader reader = new StreamReader(webclient.OpenRead(RequestUrl))) 
                    { 
                        string responseFromServer = reader.ReadToEnd(); 
                        responseFromServer = responseFromServer.Replace("&nbsp;", ""); 
                        responseFromServer = responseFromServer.Replace("&", "&amp;"); 
                        reader.Close(); 
                        webclient.Dispose(); 
                        responseFromServer = GetStringsBetweenTags(responseFromServer, "<head>", "</head>"); 
                        return responseFromServer; 
 
                    } 
 
                } 

请您参考如下方法:

下载Fiddler (http://www.fiddler2.com/fiddler2/)

然后导航到 URL 并查看 header 。然后查看您的应用程序发送的 header 。您发布的 URL 显然阻止了某些请求。