Xamarin form : Token authentication with xamarin form web api - xamarin.forms

Question

I am working with token based authentication for xamarin form here is my code
public async Task<string> checkLogin(string username, string password)
{
var keyValues = new List<KeyValuePair<string, string>>
{
new KeyValuePair<string, string>("username",username),
new KeyValuePair<string, string>("password",password),
new KeyValuePair<string, string>("grant_type","password")
};
var request = new HttpRequestMessage(HttpMethod.Post, "http://softsol.com.pk/Token");
request.Content = new FormUrlEncodedContent(keyValues);
var client = new HttpClient();
var response = await client.SendAsync(request);
var content = await response.Content.ReadAsStringAsync();
JObject jdynamic = JsonConvert.DeserializeObject<dynamic>(content);
var accessToken = jdynamic.Value<string>("access_token");
var refershToken = jdynamic.Value<string>("refresh_token");
var date = DateTime.Now.ToString();
var accessTokenExpiration= jdynamic.Value< DateTime> (".expires");
//await Application.Current.MainPage.DisplayAlert("Alert", content, "OK");
Debug.WriteLine(content);
Settings.AccessToken=accessToken;
Settings.RefreshToken = refershToken;
Settings.AccessTokenexpiration = accessTokenExpiration;
return accessToken;
//return response.IsSuccessStatusCode;
}
when I login with usernamre and password I get this error
Newtonsoft.Json.JsonReaderException: Unexpected character encountered while parsing value: <. Path '', line 0, position 0
and if I run in postman its working fine for example if I run this http://softsol.com.pk/Token in postman with username="test",password="test", grant-type="password" I get the token and its working but I get error from xamarin form. And I am stuck here

Answer 1

I visited the API part of your backend at http://softsol.com.pk/Help and I discovered that http://softsol.com.pk/Token is not there.
Moreover, testing on Postman returns a JSON response :
{
"error": "unsupported_grant_type"
}
With postman, I sent requests both in JSON:
{"username":"test","password":"test","grant-type":"password"}
and as a x-www-form-urlencoded :
I suggest you have to debug properly and analyze the Exemption information.

Answer 2

public async void GetInfoLogin()
{
IEnumerable<KeyValuePair<string, string>> member = new List<KeyValuePair<string, string>>()
{
new KeyValuePair<string, string>("username", UserName.Text),
new KeyValuePair<string, string>("password", PassWord.Text),
new KeyValuePair<string, string>("action", "get_user")
};
HttpContent content = new FormUrlEncodedContent(member);
HttpClient client = new HttpCLient();
var response = await client.PostAsync("(endpoint to server)",content);
var result = await response.Content.ReadAsStringAsync();
var TReturn = (JObject)JsonConvert.DeserializeObject(result);
var success = TReturn.Value<string>("success");
var error = TReturn.Value<string>("error");
var user_id = TReturn.Value<string>("user_id");
var full_name = TReturn.Value<string>("full_name");
var time = TReturn.Value<int>("time");
var send = TReturn.Value<string>("send");
}