如何使用 bloc 模式在存储库中注入 dataProvider答案

【问题标题】：How to inject dataProvider in repository using bloc pattern如何使用 bloc 模式在存储库中注入 dataProvider
【发布时间】：2020-12-24 02:06:17
【问题描述】：

按照bloc官方repository模式，建议使用multi-dataProvider的repository，但是如何在repository中注入dataProvider呢？

class Repository {
    final DataProviderA dataProviderA;  // What's the way to init the DataProviderA in the repository.
    final DataProviderB dataProviderB;

    Future<Data> getAllDataThatMeetsRequirements() async {
        final RawDataA dataSetA = await dataProviderA.readData();
        final RawDataB dataSetB = await dataProviderB.readData();

        final Data filteredData = _filterData(dataSetA, dataSetB);
        return filteredData;
    }
}

【问题讨论】：

标签： flutter flutter-bloc

【解决方案1】：

您可以关注官方天气示例https://bloclibrary.dev/#/flutterweathertutorial?id=repository
你可以在main() init Repository 和注入dataProviderA 和dataProviderB
代码sn-p

class Repository {
  final DataProviderA dataProviderA;
  final DataProviderB dataProviderB;

  Repository({@required this.dataProviderA, @required this.dataProviderB})
      : assert(dataProviderA != null && dataProviderB != null);

  Future<Data> getAllDataThatMeetsRequirements() async {
    final RawDataA dataSetA = await dataProviderA.readData();
    final RawDataB dataSetB = await dataProviderB.readData();

    final Data filteredData = _filterData(dataSetA, dataSetB);
    return filteredData;
  }
}

void main() {
  Bloc.observer = SimpleBlocObserver();

  final Repository repository = Repository(
    dataProviderA: DataProviderA(),
    dataProviderB: DataProviderB(),
  );

  runApp(App(repository: repository));
}

class App extends StatelessWidget {
  final Repository repository;

  App({Key key, @required this.repository})
      : assert(repository != null),
        super(key: key);

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Flutter Weather',
      home: BlocProvider(
        create: (context) => YourBloc(repository: repository),
        child: YourMainEntry(),
      ),
    );
  }
}

【讨论】：