从 API 更新数据

Question

我有以下情况，我正在从 API 获取加密货币：

class CryptocurrenciesBloc
    extends Bloc<CryptocurrenciesEvent, CryptocurrenciesState> {
  final CryptocurrencyRepository _cryptocurrencyRepository;

  CryptocurrenciesBloc(this._cryptocurrencyRepository)
      : super(CryptocurrenciesLoadInProgress()) {
    on<CryptocurrenciesFetched>(_onCryptocurrenciesFetched);
  }

  void _onCryptocurrenciesFetched(
      CryptocurrenciesFetched event, Emitter<CryptocurrenciesState> emit) async {
    try {
      final List<PopularCryptocurrency> trendingBasicInformations =
          await _cryptocurrencyRepository.fetchTrending();

      final List<String> ids = <String>[];

      for (final singleBasicInformation in trendingBasicInformations) {
        ids.add(singleBasicInformation.id);
      }

      final List<List<CryptocurrencyResponse>> cryptocurrencies =
          await Future.wait([
        _cryptocurrencyRepository.fetchCryptocurrencies(),
        _cryptocurrencyRepository.fetchCryptocurrenciesByIds(ids)
      ]);

      emit(CryptocurrenciesLoadSuccess(
          cryptocurrencies[0], cryptocurrencies[1]));
    } on Exception {
      emit(CryptocurrenciesLoadFailure());
    }
  }
}

在第一次获取加密货币后，我想每 X 秒获取一次新值（加密货币）。 我怎样才能使用 BloC 做到这一点？