如果我们在 BlocProvider 中有 3 个 BLoC,我们可以在同一个 class 中使用 2 个 BLoCBuilder 吗?

If we have 3 BLoCs in the BlocProvider, Can we use 2 BLoCBuilders in the same class?

假设我在 BlocProviderTree 中有 3 个 BLoC,这意味着这些块可用于 class。其中一个用作 BlocListener,现在我希望将其他两个 BLoC 用作 BlocBuilders,因为我需要在同一页面上构建它们的状态。 BlocListener 接受 child 而不是 children。请帮忙!

BlocListener 接受 child 而不是 children。请帮忙!

BlocProviderTree(
            blocProviders: [

              BlocProvider<EvenBloc>(bloc: _evenBloc),
              BlocProvider<SumBloc>(bloc: _sumsBloc,),
              BlocProvider<SpacesBloc>(bloc: _spacesBloc,),

            ],
            child: BlocListener(
                bloc: _evenBloc,
                listener: (BuildContext context, EvenState state) {
                  if (state is NowEven) {
                    _sumsBloc.dispatch(LoadSums());
                  }
                },

                child: BlocBuilder<SumsEvent,SumsState>(
                  bloc: _programsBloc,
                  builder: (BuildContext context, SumsState state) {
                    if (state is SumsEmpty)
                      return Container(height: 0.0, width: 0.0,);
                    if (state is SumsLoading)
                      return Evens(
                        child: SpinKitDoubleBounce(
                          color: darkIndigo,
                          size: 70.0,
                        ),
                      );
                    else if (state is SumsLoaded)
                      return _body( context,state.sums);
                  },
                )
            )
        ),

如果项目的数量是偶数,我想要带总和的 SpaceNames。我得到的总和是正确的,但 Spaces 在其他集团中。如何定义两个 BlocBuilder?

您可以相互嵌套 BlocBuilder 个:

BlocBuilder(
  bloc: BlocProvider.of<Foo>(context),
  builder: (context, FooState fooState) {
    return BlocBuilder(
      bloc: BlocProvider.of<Bar>(context),
      builder: (context, BarState barState) {
        return Text('$fooState $barState');
      },
    );
  },
);