如何在flutter_bloc V7中将此代码传输到flutter_bloc V8？

Question

问题是，我想使用emit和on

import 'package:bloc/bloc.dart';    
import 'data/repository/irepository.dart';
import 'home_event.dart';
import 'home_state.dart';
class HomeBloc extends Bloc<HomeEvent, HomeState> {
  IRepository _repository;
  HomeBloc(this._repository) : super(HomeState.initail());
  @override
  HomeState get initialState => HomeState.initail();
  // I want to replace this stream with a new version and change all the bloc 
  Stream<HomeState> mapEventToState(
      HomeEvent event,
      ) async* {
    if (event is ClearError) {
      yield state.rebuild((b) => b..error = "");
    }
 
    if (event is GetHomeData) {
      try {
        yield state.rebuild((b) => b
          ..isLoading = true
          ..error = ""
          ..isSucessGet = false
          ..GetDataHome = null);
        final slidersData = await _repository.getHomeData();
        yield state.rebuild((b) => b
          ..isLoading = false
          ..error = ""
          ..isSucessGet = true
          ..GetDataHome.replace(slidersData));
      } catch (e) {
        print('profile Error $e');
        yield state.rebuild((b) => b
          ..isLoading = false
          ..isSucessGet = false
          ..error = "Please check network connection"
          ..GetDataHome = null);
      }
    }

Answer 1

您没有共享HomeBloc的全部实现，因此这可能会有一些错误，但它应该会使您非常接近。基本上，您不再需要手动调用yield。您只需创建以相关事件和Emitter<HomeState> (或您的集团的相关State为参数)作为参数的方法，并在构造函数的on<YourEvent>部分调用该方法。

class HomeBloc extends Bloc<HomeEvent, HomeState> {
  IRepository _repository;
  HomeBloc(this._repository) : super(HomeState.initail()) {
    on<ClearError>(_onClearError);
    on<GetHomeData>(_onClearError);
  }

  Future<void> _onClearError(
    ClearError event,
    Emitter<HomeState> emit,
  ) {
    emit(state.rebuild((b) => b..error = ""));
  }

  Future<void> _onGetHomeData(
    GetHomeData event,
    Emitter<HomeState> emit,
  ) async {
    try {
      emit(state.rebuild((b) => b
        ..isLoading = true
        ..error = ""
        ..isSucessGet = false
        ..GetDataHome = null));
      final slidersData = await _repository.getHomeData();
      emit(state.rebuild((b) => b
        ..isLoading = false
        ..error = ""
        ..isSucessGet = true
        ..GetDataHome.replace(slidersData)));
    } catch (e) {
      print('profile Error $e');
      emit(state.rebuild((b) => b
        ..isLoading = false
        ..isSucessGet = false
        ..error = "Please check network connection"
        ..GetDataHome = null));
    }
  }