private async void CompleteLogin(WeChatUser user)
        {
            MessagingCenter.Unsubscribe <WeChatUser>(this, "WeChatLoggedIn");

            Debug.WriteLine("User: {0} UnionID: {1}", user.Nickname, user.UnionID);
            if (await _azure.LoginAsync(_username, user.UnionID))
            {
                if (_auth.CurrentUser != null)
                {
                    IsLoading           = false;
                    _auth.CurrentWeChat = user;

                    await _navigationService.NavigateAsync("NavigationPage/CardsListPage");
                }
            }

            LoginFailed = true;
            IsLoading   = false;
        }