flutter - 使用不包含 Bloc 类型的上下文调用的 BlocProvider.of()

Question

@override
  Widget build(BuildContext context) {
    return MultiBlocProvider(
    providers: [
         BlocProvider<TripDetailBloc>(create: (BuildContext context) => TripDetailBloc()),
         BlocProvider<PopUpBloc>(create: (BuildContext context) => PopUpBloc()),
               ],
    child: Scaffold(
      floatingActionButton: FloatingActionButton(
        child: Icon(Icons.add),
        onPressed: () {
          BlocProvider.of<TripDetailBloc>(context).add(AddTripDetailPannelEvent());
        },
      ),
      appBar: appbar(),
      body: pannel(),
    )
    );
  }

处理手势时抛出以下断言:

• BlocProvider.of() 在不包含 Bloc 类型的上下文中调用TripDetailBloc。
• 从传递给的上下文开始找不到祖先BlocProvider.of <TripDetailBloc>() .
• 如果您使用的上下文来自BlocProvider。
• 他使用的上下文是:TripDetailPage(dependencies: [MediaQuery],状态:_TripDetailPageState#d4ab3)

Answer 1

将您的代码更改为:

Widget build(BuildContext context) {
  
  return MultiBlocProvider(
      providers: [
        BlocProvider<TripDetailBloc>(create: (BuildContext context) => TripDetailBloc()),
        BlocProvider<PopUpBloc>(create: (BuildContext context) => PopUpBloc()),
      ],
      child: Builder(
        builder: (context) {
          return Scaffold(
            floatingActionButton: FloatingActionButton(
              child: Icon(Icons.add),
              onPressed: () {
                BlocProvider.of<TripDetailBloc>(context).add(AddTripDetailPannelEvent());
              },
            ),
            appBar: appbar(),
            body: pannel(),
          );
        }
      )
  );
}

如果你仔细观察，我已经将你的脚手架变成了一个小部件构建器。