HttpClient not accepting Authorization headers (401 Unauthorized)

[dush88c]

I have used System.Net.Http to create an HTTP client to access the Web API GET method which is authorized as below. But it returns unauthorized (401) error always even if it works fine in Postman with same authorization token (Bearer)

using (var ProfileClient = new HttpClient())
            {
                var token = OAuthToken.Instance.AccessToken;
                ProfileClient.DefaultRequestHeaders.Authorization = new AuthenticationHeaderValue("Bearer", token);
                
                var response = await ProfileClient.GetAsync(AppSettings.AbbottAuthorizationProfileUrl);
                
                if (response.StatusCode == System.Net.HttpStatusCode.OK)
                {
                    return CheckProfileReturn(response);
                }
                else if (response.StatusCode == System.Net.HttpStatusCode.Unauthorized)
                {
                    return new Tuple<bool, string>(false, "Unauthorized access");
                }
                else
                {
                    var result = await response.Content.ReadAsStringAsync();
                    var errorModel = JsonConvert.DeserializeObject<OauthError>(result);
                    return new Tuple<bool, string>(false, errorModel?.ErrorDescription);
                }
            }

I have no idea why this is not working in Xamarin.Forms httpclient ?
Versions
Xamarin Forms : 2.4.0.280
System.Net.Http : MonoAndroid\v1.0\4.0.30319

.Net : 4.5

Thanks

[rmarinho]

Hi this doesn't seem a issue related with Xamarin.Forms itself.

Trying to help you might want to migrate to use the latest version of Xamarin Forms like 3.2.0 that uses netstandard .

You should inspect the headers of the call to see how the request is form. also might want to check if its a https issue or something.

Feel free to reopen if you figure is something wrong with Xamarin.Forms.

Thanks

[Adincodavid]

@dush88c dis you solved this issue??
I have the same problem

[dush88c]

In my case, there was '/' at end of the url. Once it's removed. It worked.

[amirvenus]

I have the same issue
I can obtain the token using MSAL and in fact, I can use that bearer token in Postman but when I pass it to my HttpClient, I keep getting 401.

I think this is rather a mono bug...

[poorankharol]

I have the same issue does not work on android app but works on postman

[Mirazyzz]

@amirvenus @rmarinho did you found out the reason of this issue?