OneDrive Service don't get a refresh token - onedrive

Question

I use Xamarin.Auth to authenticate with the OneDrive Service. This worked fine for a while now, but I seems there where changes on the service so it stopped working..
I upgraded to the new version 2.0 and try to make it work again. The Initial authentication works well so far. But after a while it always started to crash. I realized that there isn't any refrehs token sent back from the onedrive service.
This is the code to call the Auth UI:
private Task<IDictionary<string, string>> ShowWebView()
{
var tcs = new TaskCompletionSource<IDictionary<string, string>>();
var auth = new OAuth2Authenticator(ServiceConstants.MSA_CLIENT_ID,
string.Join(",", ServiceConstants.Scopes),
new Uri(GetAuthorizeUrl()),
new Uri(ServiceConstants.RETURN_URL));
auth.Completed +=
(sender, eventArgs) =>
{
tcs.SetResult(eventArgs.IsAuthenticated ? eventArgs.Account.Properties : null);
};
var intent = auth.GetUI(Application.Context);
intent.SetFlags(ActivityFlags.NewTask);
Application.Context.StartActivity(intent);
return tcs.Task;
}
private string GetAuthorizeUrl()
{
var requestUriStringBuilder = new StringBuilder();
requestUriStringBuilder.Append(ServiceConstants.AUTHENTICATION_URL);
requestUriStringBuilder.AppendFormat("?{0}={1}", ServiceConstants.REDIRECT_URI,
ServiceConstants.RETURN_URL);
requestUriStringBuilder.AppendFormat("&{0}={1}", ServiceConstants.CLIENT_ID,
ServiceConstants.MSA_CLIENT_ID);
requestUriStringBuilder.AppendFormat("&{0}={1}", ServiceConstants.SCOPE,
WebUtility.UrlEncode(string.Join(" ", ServiceConstants.Scopes)));
requestUriStringBuilder.AppendFormat("&{0}={1}", ServiceConstants.RESPONSE_TYPE, ServiceConstants.CODE);
return requestUriStringBuilder.ToString();
}
The Authorize URI is:
https://login.live.com/oauth20_authorize.srf?redirect_uri=https://login.live.com/oauth20_desktop.srf&client_id=["id"]&scope=onedrive.readwrite+wl.offline_access+wl.signin&response_type=code
The response I get contains 6 Elements:
access_token: "EwAIA..."
token_type: "bearer"
expires_in: "3600"
scope: "onedrive.readwrite wl.offline_access wl.signin wl.basic wl.skydrive wl.skydrive_update onedrive.readonly"
user_id: "41...."
state: "ykjfmttehzjebqtp"
When I check it with the Documentation (https://dev.onedrive.com/auth/msa_oauth.htm) I can't see what's wrong here. Any ideas?

Answer 1

I called wrong constructor. This one works:
authenticator = new OAuth2Authenticator(ServiceConstants.MSA_CLIENT_ID,
ServiceConstants.MSA_CLIENT_SECRET,
string.Join(",", ServiceConstants.Scopes),
new Uri(ServiceConstants.AUTHENTICATION_URL),
new Uri(ServiceConstants.RETURN_URL),
new Uri(ServiceConstants.TOKEN_URL));
With these constants:
Scopes = {"onedrive.readwrite", "wl.offline_access", "wl.signin"};
RETURN_URL = "https://login.live.com/oauth20_desktop.srf";
AUTHENTICATION_URL = "https://login.live.com/oauth20_authorize.srf";
TOKEN_URL = "https://login.live.com/oauth20_token.srf";