集团陷入收益负载

Question

我正在尝试计算距离，这是我要做的

@override
  Stream<StoreState> mapEventToState(StoresEvent event) async* {
    final currentState = state;
    if (event is FetchStores) {
      yield StoreLoading();
      try {
        List<Stores> dataChild = await _fetchStores();
        yield StoreLoaded(stores: dataChild);
      } catch (e) {
        yield StoreError(message: e.toString());
      }
    }
    if (event is SortStore) {
      print(event);
      yield StoreLoading();
      if (currentState is StoreLoaded) {
        print(currentState);
        currentState.stores.forEach((storeData) {
          storeData.storeDistance = calculateDistance(event.latitude, event.longitude, storeData.storeLatitude, storeData.storeLongitude);
        });
        currentState.stores
            .sort((a, b) => a.storeDistance.compareTo(b.storeDistance));
        yield StoreLoaded(stores: currentState.stores);
      }
    }
  }

这是calculateDistance()

calculateDistance(double userLatitude, double userLongitude,
      String storeLatitude, String storeLongitude) async {
    var storeDistance = 0.0;
    if (userLongitude != 0.0) {
      var list = (await Geolocator().distanceBetween(
          userLatitude,
          userLongitude,
          double.parse(storeLatitude),
          double.parse(storeLatitude)));
      storeDistance = list / 1000;
      print(storeDistance.toString());
      return storeDistance.toString();
    }
  }

我怎么称呼它

FloatingActionButton(
        onPressed: (){
          print(_currentLatitude);
          print(_currentLongitude);
          storesBloc.add(SortStore(latitude:_currentLatitude, longitude: _currentLongitude));
          },
      ),

对于第一次加载，数据显示正常（FetchStoresEvent()），但是当我单击FloatingActionButton（运行SortStore()事件）时，数据未显示。它停留在yield StoreLoading();上。我该如何解决？

顺便说一句，这是我从日志中看到的内容

I/flutter (25608): -6.1300483
I/flutter (25608): 106.91085
I/flutter (25608): SortStore
I/flutter (25608): StoreLoaded
I/flutter (25608): 12492.154