假设有一个名为 PreferenceBloc 的顶级 BLoC,而在该 BLoC 内部是另一个名为 PageBloc 的 BLoC。如果 PageBloc 内部的逻辑需要来自 PreferenceBloc 的值流(即,创建一个新页面现在需要知道页面配置),我应该如何构建它?
代码示例:
class PreferencesBloc{
final preferencesService=PreferencesService();
// Output interfaces of Bloc
ValueObservable<String> get mainDir => _mainDir.distinct().shareValue(seedValue: '/');
final _mainDir = BehaviorSubject<String>(seedValue: '/');
// Input interfaces of Bloc...
// .........
}
class PageBloc{
final List<PageInfo> _pageInfos=<PageInfo>[];
// Output interfaces of Bloc...
// .........
// Input interfaces of Bloc...
Sink<int> get pageCreation => _pageCreationController.sink;
final _pageCreationController = StreamController<int>();
pageBloc(){
_pageCreationController.stream.listen(_handleCreation);
}
void _handleCreation(int pos){
_pageInfo.insert(pos, PageInfo('I need the mainDir here!')); //Need info from PreferencesBloc!!!
}
}
class PreferencesProvider extends InheritedWidget{
final PreferencesBloc preferencesBloc;
//...
}
class PageProvider extends InheritedWidget{
final PageBloc pageBloc;
//...
}
void main() => runApp(MyApp());
class MyApp extends StatelessWidget {
@override
Widget build(BuildContext context) {
return PreferencesProvider(
child: PageProvider(
child: MaterialApp(
home: Scaffold(
body: Text("test"),
),
),
),
);
}
}
编辑:综上所述,flutter中Bloc和widget之间的通信很方便,但是Bloc和Bloc之间有没有好的通信方式呢?