flutter - RxDart。 BehaviorSubject的监听器在subject.add(value)之后不获取值

我有两个类:CurrencyRepo和CurrencyFetcher。从CurrencyFetcher，我尝试收听回购中的behaviorSubject。但是，当我在回购内的behaviorSubject中添加值时，CurrencyFetcher无法获取这些值。我究竟做错了什么？

class CurrencyFetcher implements CurrencyFetcherService {
  final CurrencyRepo _currencyRepo;
  StreamSubscription currencySubscription;

  CurrencyFetcher(this._currencyRepo, this._preferencesService) {
    _subscribeToCurrencies();
  }

  void _subscribeToCurrencies() {
    currencySubscription = _currencyRepo
        .getCurrenciesStream()
        .listen((currencies) => _handleApiCurrencies);
  }

  Future<void> _handleApiCurrencies(List<ApiCurrency> apiCurrencies) async {
  // implemetation
  }
}

class CurrencyRepo {
  final CurrencyApi _currencyApi;
  final BehaviorSubject<List<ApiCurrency>> _currencySubject = BehaviorSubject.seeded([]);

  Stream<List<ApiCurrency>> getCurrenciesStream() {
    _updateCurrencies();
    return _currencySubject.stream;
  }

  CurrencyRepo(this._currencyApi);

  void _updateCurrencies() {
    _currencyApi.getCurrencies().then((currencies) {
      _currencySubject.add(currencies);
    });
  }
}

我检查了CurrencyFetcher开始侦听后是否将值添加到了流中。我检查了一下，当我向流添加新值时，它具有一个侦听器。第一次使用RxDart，有人可以帮忙吗？ :)

最佳答案

在函数_subscribeToCurrencies()里面尝试写

_currencyRepo.currenciesStream.listen((currencies) {
      _handleApiCurrencies(currencies);
});

代替

_currencyRepo.currenciesStream.listen(_handleApiCurrencies);

关于flutter - RxDart。 BehaviorSubject的监听器在subject.add(value)之后不获取值，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/63504577/