异步方法似乎没有在流中等待

Question

我想知道是否有人可以帮助我进行身份验证。我收到间歇性错误。我的应用程序中的路由基本上取决于从 newUser 返回的 SharedPreferences 。在代码中，返回的状态取决于 _mapAuthenticationUserChangedToState 中的逻辑。但是，有时事件不会“足够快”地从 SP 读取并且路由错误。即使路由有效......我可以从应用程序的日志中看到，即使路由是正确的，它不应该路由到的屏幕的 initState 被调用。我的代码中是否有任何明显的错误。 ..（也可能写到 SP 不够快，我是我的社交登录流程）

class AuthenticationBloc extends Bloc<AuthenticationEvent, AuthenticationState> {
      AuthenticationBloc({
        @required AuthenticationRepository authenticationRepository,
      })  : assert(authenticationRepository != null),
            _authenticationRepository = authenticationRepository,
            super(const AuthenticationState.unknown()) {
        _userSubscription = _authenticationRepository.user.listen(
          (user) => add(AuthenticationUserChanged(user, user.isNewUser)),
        );
      }
    
      final AuthenticationRepository _authenticationRepository;
      StreamSubscription<PraxUser> _userSubscription;
    
      @override
      Stream<AuthenticationState> mapEventToState(
        AuthenticationEvent event,
      ) async* {
        if (event is AuthenticationUserChanged) {
          var userRepository = UserRepository();
          final DeviceInfoPlugin deviceInfoPlugin = new DeviceInfoPlugin();
          SharedPreferences prefs = await SharedPreferences.getInstance();
    
          bool isNewUser = prefs.getBool('is_new_user') ?? false;
    
          yield _mapAuthenticationUserChangedToState(event, isNewUser);
        } else if (event is AuthenticationLogoutRequested) {
          unawaited(_authenticationRepository.logOut());
        }
      }
    
      @override
      Future<void> close() {
        _userSubscription?.cancel();
        return super.close();
      }
    
      AuthenticationState _mapAuthenticationUserChangedToState(
        AuthenticationUserChanged event,
        bool isNewUser,
      ) {
        if (event.user != PraxUser.empty) {
          if (isNewUser) {
            return AuthenticationState.signedUp(event.user);
          } else {
            return AuthenticationState.authenticated(event.user);
          }
        } else {
          return AuthenticationState.unauthenticated();
        }
      }
    }

编辑：

else if (state is SignUpSuccess) {
                    Navigator.of(context).popUntil((route) => route.isFirst);
                    BlocProvider.of<AuthenticationBloc>(context).add(AuthenticationUserChanged(state.user, true));
                  } else if (state is AlreadySignedUpSuccess) {
                    Navigator.of(context).popUntil((route) => route.isFirst);
                    BlocProvider.of<AuthenticationBloc>(context).add(AuthenticationUserChanged(state.user, false));

编辑：

我的 main.dart 有一个监听器

return BlocListener<AuthenticationBloc, AuthenticationState>(
          listener: (context, state) {
            final id = state.user.id;

            switch (state.status) {
              case AuthenticationStatus.signedUp:
                _navigator.pushNamedAndRemoveUntil<void>(
                  AppRouter.onboarding,
                  (route) => false,
                );
                break;
              case AuthenticationStatus.authenticated:
                _navigator.pushNamedAndRemoveUntil<void>(
                  AppRouter.home,
                  (route) => false,
                );
                break;
              case AuthenticationStatus.unauthenticated:
                _navigator.pushNamedAndRemoveUntil<void>(
                  AppRouter.intro,
                  (route) => false,
                );
                break;
              default:
                break;
            }