I wrote the following program in C# using .NET 4.7.1:
var req = (HttpWebRequest) WebRequest.Create(myUrl);
req.AllowAutoRedirect = false;
var rsp = req.GetResponse();
Console.WriteLine(rsp.Headers["Location"]);
The site I am requesting from is returning a 301 response, and the "Location" header contains the URL to redirect to.
If I do the exact same thing using .NET Core 2.1, I will instead get a WebException
thrown from the call to GetResponse
. How can I avoid this?
Based on this, you need to trap it in try/catch
block and inspect the WebException
:
If you set
AllowAutoRedirect
, then you will end up not following the redirect. That means ending up with the 301 response.HttpWebRequest
(unlikeHttpClient
) throws exceptions for non-successful (non-200) status codes. So, getting an exception (most likely aWebException
) is expected. So, if you need to handle that redirect (which is HTTPS -> HTTP by the way), you need to trap it in try/catch block and inspect the WebException etc. That is standard use ofHttpWebRequest
.That is why we recommend devs use
HttpClient
which has an easier use pattern.
Something like this:
WebResponse rsp;
try
{
rsp = req.GetResponse();
}
catch(WebException ex)
{
if(ex.Message.Contains("301"))
rsp = ex.Result;
}