Facebook OAuth Xamarin Forms Redirect

Question

I use xamarin OAuth2 forms to login to Facebook, Google and Twitter.

In android it works. But on iOS, this screen freezes with a spinning activity indicator in the upper right corner. Does anyone have one problem?

Update: see below code

partial void UIButton15_TouchUpInside(UIButton sender)
{
    // https://developers.facebook.com/apps/
    var auth = new OAuth2Authenticator(
    clientId: "ID",
    scope: "",
    authorizeUrl: new Uri("https://m.facebook.com/dialog/oauth/"),
    redirectUrl: new Uri("http://www.facebook.com/connect/login_success.html"));

    var ui = auth.GetUI();

    auth.Completed += FacebookAuth_Completed;

    PresentViewController(ui, true, null);
}

async void FacebookAuth_Completed(object sender, AuthenticatorCompletedEventArgs e)
{
    if (e.IsAuthenticated)
    {
        var request = new OAuth2Request(
            "GET",
            new Uri("https://graph.facebook.com/me?fields=name,picture,cover,birthday"),
            null,
            e.Account);

        var fbResponse = await request.GetResponseAsync();
        var fbUser = JsonValue.Parse(fbResponse.GetResponseText());
        var name = fbUser["name"];
        var id = fbUser["id"];
        var picture = fbUser["picture"]["data"]["url"];
        var cover = fbUser["cover"]["source"];
    }
    DismissViewController(true, null);
}

On the facebook developer website:

Created an application that uses the plugin to enter Facebook. Added redirect URL as http://www.facebook.com/connect/login_success.html

Answer 1

, OAuth. OAuth - . , Webview API-.