Question

我关注This Page以及来自Xamarin.Auth github repo的一些示例，因此设置了facebook登录名。我创建了以下登录功能：

//table[@class="magic"]//tr[@class="head"  and ./th[contains(., "United States")]]/following-sibling::tr[@class="section-break"][1]

但是我在最后一行得到以下异常：

public void Authenticate()
{
    string clientId = Config.FacebookAppID;
    string redirectUri = redirectUri = "MyApp:/authorize";
    var authenticator = new OAuth2Authenticator(
        clientId: clientId,
        scope: "public_profile,email",
        authorizeUrl: new Uri("https://www.facebook.com/v2.9/dialog/oauth"),
        redirectUrl: new Uri(redirectUri),
        getUsernameAsync: null,
        isUsingNativeUI: true);

    authenticator.AllowCancel = true;
    authenticator.Completed += OnAuthCompleted;
    authenticator.Error += OnAuthError;
    Authenticator = authenticator;

    var presenter = new Xamarin.Auth.Presenters.OAuthLoginPresenter();
    presenter.Login(Authenticator);
}

任何想法我可能做错了什么？

Answer 1

我知道这已经有一年多了，但是，在经过指导的链接式培训之后，我遇到了同样的问题。

答案是在AuthenticationConfiguration类的FinishedLaunching方法中初始化AppDelegate。

public override bool FinishedLaunching(UIApplication application, NSDictionary launchOptions)
{
    // Override point for customization after application launch.
    // If not required for your application you can safely delete this method
    // Add the Init() method here
    global::Xamarin.Auth.Presenters.XamarinIOS.AuthenticationConfiguration.Init();
    return true;
}

Xamarin.Auth Facebook给出了NullReferenceException 2

1 个答案: