Question

I am trying to obtain the headers of a webpage. The code block below does the job.
However, when a page is 401 denied, I can’t get any headers at all. Is there a way?

Thanks

public Int32 CheckURLStatus(string uri, out HttpWebResponse _response)
    {
        //Get response header
        _response = null;
        ServicePointManager.SecurityProtocol = SecurityProtocolType.Ssl3;
        HttpWebRequest _request = (HttpWebRequest)WebRequest.Create(uri);
        _request.Method = "GET";
        _request.AllowAutoRedirect = true;
        _request.Accept = "*/*";
        _request.MaximumAutomaticRedirections = 4;
        _request.UseDefaultCredentials = true;
        _request.Credentials = System.Net.CredentialCache.DefaultNetworkCredentials;
        Int32 statusCode = 404;
        try
        {
            _response = (HttpWebResponse)_request.GetResponse();
            statusCode = Convert.ToInt32(_response.StatusCode);
        }
        catch (Exception ex)
        {
            _response = null;
        }
        return statusCode;
    }

Answer 1

In case of any StatusCode that is not 200 the GetResponse() method throws a WebException. To get the status code you have to handle this Exception and get the StatusCode from the Response that is in the Exception.

I´ve changed your code to get the response code even in the case of WebException:

public Int32 CheckURLStatus(string uri, out HttpWebResponse _response)
    {
        //Get response header
        _response = null;
        ServicePointManager.SecurityProtocol = SecurityProtocolType.Ssl3;
        HttpWebRequest _request = (HttpWebRequest)WebRequest.Create(uri);
        _request.Method = "GET";
        _request.AllowAutoRedirect = true;
        _request.Accept = "*/*";
        _request.MaximumAutomaticRedirections = 4;
        _request.UseDefaultCredentials = true;
        _request.Credentials = System.Net.CredentialCache.DefaultNetworkCredentials;
        Int32 statusCode = 404;
        try
        {
            _response = (HttpWebResponse)_request.GetResponse();
            statusCode = Convert.ToInt32(_response.StatusCode);
        }
        catch (WebException ex)
        {
            statusCode = Convert.ToInt32(((HttpWebResponse)ex.Response).StatusCode);
            _response = null;
        }
        return statusCode;
    }

Also you can check the ex.Response.Headers and you will have the HTTP headers of the response.