我尝试在宠物项目中使用依赖注入（get_it）和块（flutter_bloc）。但我遇到了下面所示的问题。

I/flutter (23661): Error while creating WeatherInfoLocalDataSource
I/flutter (23661): Error while creating WeatherInfoRepository
I/flutter (23661): Error while creating GetWeatherInfoByCityName
I/flutter (23661): Error while creating WeatherInfoBloc
════════ Exception caught by widgets library ═══════════════════════════════════
The following assertion was thrown building _BodyBuilder:
You tried to access an instance of SharedPreferences that is not ready yet
'package:get_it/get_it_impl.dart':
package:get_it/get_it_impl.dart:1
Failed assertion: line 404 pos 9: 'instanceFactory.isReady'

The relevant error-causing widget was
Scaffold
lib\…\pages\weather_info_page.dart:25
When the exception was thrown, this was the stack
════════ Exception caught by rendering library ═════════════════════════════════
Each child must be laid out exactly once.
The relevant error-causing widget was
Scaffold

我看了github，stackoverflow上的文章，也看了教程中的代码，但是不明白我做错了什么。有人能解释一下我做错了什么吗？代码：注射容器

final sl = GetIt.instance;

void init() {
  //! Features - Weather Check
  // Bloc

  sl.registerFactory(() => WeatherInfoBloc(
        concrete: sl(),
        random: sl(),
        inputConverter: sl(),
      ));

  // UseCases
  sl.registerLazySingleton(() => GetWeatherInfoByCityName(sl()));
  sl.registerLazySingleton(() => GetWeatherByRandomCity(sl()));

  // Repository
  sl.registerLazySingleton<WeatherInfoRepository>(
      () => WeatherInfoRepositoryImpl(
            localDataSource: sl(),
            remoteDataSource: sl(),
            networkInfo: sl(),
          ));

  // Data
  sl.registerLazySingleton<WeatherInfoRemoteDataSource>(
      () => WeatherInfoRemoteDataSourceImpl(httpClient: sl()));

  sl.registerLazySingleton<WeatherInfoLocalDataSource>(
      () => WeatherInfoLocalDataSourceImpl(sharedPreferences: sl()));

  //! Core
  sl.registerLazySingleton(() => InputConverter());
  sl.registerLazySingleton<NetworkInfo>(() => NetworkInfoImpl(sl()));

  //! External
  sl.registerSingletonAsync<SharedPreferences>(
      () => SharedPreferences.getInstance());

  sl.registerLazySingleton(() => http.Client);
  sl.registerLazySingleton(() => InternetConnectionChecker());
}

主要的

void main() async {
  WidgetsFlutterBinding.ensureInitialized();
  di.init();
  runApp(const MyApp());
}

class MyApp extends StatelessWidget {
  const MyApp({Key? key}) : super(key: key);

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      debugShowCheckedModeBanner: true,
      theme: ThemeData(primaryColor: Colors.lightBlue.shade800),
      home: BlocProvider<WeatherInfoBloc>(
        create: (_) => di.sl<WeatherInfoBloc>(),
        child: const WeatherInfoPage(),
      ),
    );
  }
}

天气信息页面

class WeatherInfoPage extends StatefulWidget {
  const WeatherInfoPage({Key? key}) : super(key: key);

  @override
  State<WeatherInfoPage> createState() => _WeatherInfoPageState();
}

class _WeatherInfoPageState extends State<WeatherInfoPage> {
  //late final WeatherInfoBloc _weatherInfoBloc;

  // @override
  // void initState() {
  //   super.initState();
  //   //_weatherInfoBloc = sl<WeatherInfoBloc>();
  //   //_weatherInfoBloc.add(const WeatherInfoEvent.loadArticles());
  // }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: const Text('Weather info'),
      ),
      body: Center(
          child: Padding(
        padding: const EdgeInsets.all(8),
        child: _buildBody(context),
      )),
    );
  }

  Widget _buildBody(BuildContext context) {
    return Column(
      children: <Widget>[
        BlocBuilder<WeatherInfoBloc, WeatherInfoState>(
          builder: (context, state) {
            if (state is Empty) {
              return const MessageDisplay(
                message: 'Start searching!',
              );
            } else if (state is Loading) {
              return const LoadingWidget();
            } else if (state is Loaded) {
              return WeatherDisplay(weatherInfo: state.weatherInfo);
            } else if (state is Error) {
              return MessageDisplay(
                message: state.message,
              );
            }
            return const SizedBox.shrink();
          },
        ),
        // SizedBox(
        //   height: MediaQuery.of(context).size.height / 3,
        //   child: const Placeholder(),
        // ),
        const SizedBox(
          height: 30,
          child: SizedBox.shrink(),
        ),
        const WeatherControls(),
      ],
    );
  }

  Widget _buildBloc(BuildContext context) {
    return BlocBuilder<WeatherInfoBloc, WeatherInfoState>(
      builder: (context, state) {
        if (state is Empty) {
          return const MessageDisplay(
            message: 'Start searching!',
          );
        } else if (state is Loading) {
          return const LoadingWidget();
        } else if (state is Loaded) {
          return WeatherDisplay(weatherInfo: state.weatherInfo);
        } else if (state is Error) {
          return MessageDisplay(
            message: state.message,
          );
        }
        return const SizedBox.shrink();
      },
    );
  }
}

如有必要，我将用其他文件补充代码。
UPD：通过添加await di.sl.allReady（）解决;int n = int n（）;在注入过程中，容器忘记给http.Client添加括号，也忘记在与bloc关联的方法中添加await。