hydrated_bloc:参数'storageDirectory‘是必需的

import 'package:flutter/material.dart';
import 'package:hydrated_bloc/hydrated_bloc.dart';

void main() {
  WidgetsFlutterBinding.ensureInitialized();
  HydratedBloc.storage = await HydratedStorage.build(
    storageDirectory: Directory.systemTemp.path,
  );
  runApp(MyApp());
}

<!-- Android -->
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>
<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE"/>

final directory = Directory(storageDirectory);
if (!await directory.exists()) {
  await directory.create(recursive: true);
}

import 'package:flutter/material.dart';
import 'package:hydrated_bloc/hydrated_bloc.dart';

void main() async {
  WidgetsFlutterBinding.ensureInitialized();
  final storageDirectory = Directory.systemTemp.path;
  HydratedBloc.storage = await HydratedStorage.build(
    storageDirectory: storageDirectory,
  );
  runApp(MyApp());
}

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      home: BlocProvider(
        create: (context) => MyBloc(),
        child: MyHomePage(),
      ),
    );
  }
}

class MyBloc extends HydratedBloc<MyEvent, MyState> {
  MyBloc() : super(MyInitial());

  @override
  MyState? fromJson(Map<String, dynamic> json) {
    // Implement deserialization logic here
  }

  @override
  Map<String, dynamic> toJson(MyState state) {
    // Implement serialization logic here
  }

  @override
  Stream<MyState> mapEventToState(MyEvent event) async* {
    // Implement event handling logic here
  }
}