BlocProvider<B extends BlocBase<S> , S> constructor
BlocProvider<B extends BlocBase<S> , S> (
- Create<
B, ProviderReference> create, { - String? name,
BlocProvider
Similar to StateNotifierProvider
but for BlocBase (Bloc and Cubit)
class CounterCubit extends Cubit<int> {
CounterCubit(int state) : super(state);
void increment() => emit(state + 1);
}
final counterProvider =
BlocProvider<CounterCubit, int>((ref) => CounterCubit(0));
class MyHomePage extends ConsumerWidget {
const MyHomePage({Key? key, required this.title}) : super(key: key);
final String title;
@override
Widget build(BuildContext context, ScopedReader watch) {
// Rebuilds the widget if the cubit/bloc changes.
// But does not rebuild if the state changes with the same cubit/bloc
final counterCubit = watch(counterProvider.notifier);
return Scaffold(
appBar: AppBar(
title: Text(title),
),
body: Center(
child: Column(
mainAxisAlignment: MainAxisAlignment.center,
children: <Widget>[
Text(
'initial counterCubit.state: ${counterCubit.state}',
),
Consumer(builder: (context, watch, __) {
// Rebuilds on every emitted state
final _counter = watch(counterProvider);
return Text(
'$_counter',
style: Theme.of(context).textTheme.headline4,
);
}),
],
),
),
floatingActionButton: FloatingActionButton(
onPressed: () => context.read(counterProvider.notifier).increment(),
tooltip: 'Increment',
child: Icon(Icons.add),
),
);
}
}
Implementation
BlocProvider(
Create<B, ProviderReference> create, {
String? name,
}) : _create = create,
super(name);