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Question

我正在使用Auth0Client for Windows Phone 8.0项目。我遇到了Auth0.SDK.AuthenticationCancelException的问题 - 因为在点击LoginFacebookTap按钮后我一直按下后退按钮就会崩溃我的应用程序。

所以当我加载应用程序时，我转到LoginView页面，并且有一个按钮，它将调用：

private async void LoginFacebookTap(object sender, System.Windows.Input.GestureEventArgs e)
{
    var result = await authorizationService.LoginAuth0(AuthorizationService.AuthorizationServiceType.Facebook, "", "");
    if (result == true)
    {
        MessageBox.Show("OK!");
    }
}

这就是我的方法LoginAuth0

public async Task<Boolean> LoginAuth0(AuthorizationServiceType type, string email, string password)
{
    if (NetworkService.IsNetworkAvailable())
    {
        try
        {
            Auth0User user;
            switch (type)
            {
                case AuthorizationServiceType.EmailAndPassword:
                    user = await auth0.LoginAsync(Constants.login_with_password_Auth0, email, password);
                    break;
                case AuthorizationServiceType.Email:
                    user = await auth0.LoginAsync(Constants.login_azure_Auth0);
                    break;
                case AuthorizationServiceType.Facebook:
                    user = await auth0.LoginAsync(Constants.login_facebook_Auth0);
                    break;
                case AuthorizationServiceType.Google:
                    user = await auth0.LoginAsync(Constants.login_google_Auth0);
                    break;
                case AuthorizationServiceType.Linkedin:
                    user = await auth0.LoginAsync(Constants.login_linkedin_Auth0);
                    break;
                case AuthorizationServiceType.Twitter:
                    user = await auth0.LoginAsync(Constants.login_twitter_Auth0);
                    break;
                case AuthorizationServiceType.Windows:
                    user = await auth0.LoginAsync(Constants.login_windows_Auth0);
                    break;
            }
        }
        catch (AuthenticationCancelException)
        {
            System.Diagnostics.Debug.WriteLine("User press cancel on Authentication");
            return false;
        }
        catch (AuthenticationErrorException ex)
        {
            MessageBox.Show(Resources.AppResources.TitleError + " : " + ex.Message);
            return false;
        }
        catch (Exception exc)
        {
            MessageBox.Show(Resources.AppResources.MessageErrorUserNotExists);
            System.Diagnostics.Debug.WriteLine("Unknown exception: "+exc.Message);
            return false;
        }

        try
        {
            var targetClientId = Constants.clientId_Auth0;
            var options = new Dictionary<string, string>
            {
                { "scope", "openid profile" }
            };
            var delegationResult = await auth0.GetDelegationToken(targetClientId, options);

            if (delegationResult != null)
            {
                String jsonString = delegationResult["id_token"].ToString();
                System.Diagnostics.Debug.WriteLine("Application received token: " + jsonString);
                return true;
            }
            else MessageBox.Show(AppResources.MessageErrorSigning);
        }
        catch(Exception exc)
        {
            MessageBox.Show(Resources.AppResources.TitleError +" : " + exc.Message);
        }
        return false;
    }
    else
    {
        MessageBox.Show(Resources.AppResources.MessageErrorNoConnection);
        return false;
    }
}

点击LoginFacebookTap后按“返回”按钮，结果为：

类型的第一次机会异常 'Auth0.SDK.AuthenticationCancelException'发生在 Auth0Client.Phone.Silverlight.ni.DLL类型的第一次机会异常 mscorlib.ni.dll中发生'Auth0.SDK.AuthenticationCancelException' 类型的第一次机会异常 mscorlib.ni.dll中发生'Auth0.SDK.AuthenticationCancelException' “System.InvalidOperationException”类型的第一次机会异常发生在Microsoft.Phone.ni.dll

然后应用程序崩溃“InvalidOperationException当CanGoBack为false时无法返回。”这是bug还是？

更新

我发现，只有当您登录到自己的Facebook帐户并且通过身份验证时才会发生这种情况。然后，当您再次运行应用程序并单击LoginFacebookTap时，您将不会重定向到Facebook登录页面，但您将自动重定向并返回“OK”验证结果。在重定向回LoginView之前，您会看到白屏，当您按Back时，将返回“InvalidOperationException当CanGoBack为false时无法返回。”

更新2

我在Auth0.SDK中发现了什么：

/// <summary>
/// Handler for the browser control's navigation failed event.  We use this to detect errors
/// </summary>
private void BrowserControl_NavigationFailed(object sender, NavigationFailedEventArgs e)
{
    WebBrowserNavigationException navEx = e.Exception as WebBrowserNavigationException;

    if (navEx != null)
    {
        // Pass along the provided error information.
        responseErrorDetail = string.Format("Error code: {0}", navEx.StatusCode);
    }
    else
    {
        // No error information available.
        responseErrorDetail = NoDetailsAvailableMessage;
    }
    responseStatus = PhoneAuthenticationStatus.ErrorHttp;

    authenticationFinished = true;
    e.Handled = true;

    // Navigate back now.
    this.NavigateBackWithProgress();
}

/// <summary>
/// Displays the progress bar and navigates to the previous page.
/// </summary>
private void NavigateBackWithProgress()
{
    ShowProgressBar();
    NavigationService.GoBack();
}

在NavigationService.GoBack（）;我们有InvalidOperationException当CanGoBack为false时无法返回。

Answer 1

是的，当您取消身份验证时，SDK会引发异常。你正在捕捉它，所以没关系

Answer 2

SDK上的错误：

private void NavigateBackWithProgress()
 {
     ShowProgressBar();
    if(NavigationService.CanGoBack)
        NavigationService.GoBack();
 }

在调用NavigationService.GoBack（）之前，我们应该始终检查后端堆栈上是否有偶数页面。它还涉及：

private void NavigateBackWithProgress()
 {
     ShowProgressBar();
    if(this.Frame != null && this.Frame.CanGoBack)
        this.Frame.GoBack();
 }

Windows Phone 8.0项目中的Auth0.SDK.AuthenticationCancelException

更新

更新2

2 个答案: