Why isn't the screen rebuild in flutter bloc? - flutter

Question

I split the screen into 2 parts, the upper part to change the state when each time I clicked, the bottom part is a list, when the state is loaded, I try to add an event to sort, it still works but the screen don't rebuild again
My code here
Hope everyone can help! Thank
widget
Scaffold(
backgroundColor: Colors.white,
body: SafeArea(
child: BlocProvider(
create: (_) => referrerBloc,
child: Column(
children: [
flag1(referrerBloc.add(ReferrerSortEvent)),
flag2(referrerBloc.add(ReferrerSortEvent)),
flag3(referrerBloc.add(ReferrerSortEvent)),
BlocBuilder<ReferrerBloc, ReferrerState>(
builder: (__, state) {
if (state is ReferrerLoadingState) {
referrerBloc.add(ReferrerLoadedEvent());
return const Center(
child: CircularProgressIndicator(),
);
} else if (state is ReferrerLoadedState) {
final listReferrer = state.listReferrer;
return Expanded(
child: ListView.builder(
itemCount: listReferrer.length,
itemBuilder: (context, index) {
return Container(
padding: const EdgeInsets.symmetric(
horizontal: 16,
),
child: itemUser(listReferrer.elementAt(index)),
);
},
),
);
}
return const Center(
child: Text(
'Error!',
style: TextStyle(color: Colors.red),
),
);
},
),
],
),
),
),
)
My code here Hope everyone can help! Thank
My code here Hope everyone can help! Thank
event
part of 'referrer_bloc.dart';
abstract class ReferrerEvent extends Equatable {
const ReferrerEvent();
#override
List<Object> get props => [];
}
class ReferrerLoadingEvent extends ReferrerEvent {}
class ReferrerLoadedEvent extends ReferrerEvent {}
class ReferrerSortEvent extends ReferrerEvent {
const ReferrerSortEvent({required this.flag, required this.time});
final int flag;
final int time;
}
class ReferrerErrorEvent extends ReferrerEvent {}
My code here Hope everyone can help! Thank
My code here Hope everyone can help! Thank
state
part of 'referrer_bloc.dart';
abstract class ReferrerState extends Equatable {
const ReferrerState();
}
class ReferrerLoadingState extends ReferrerState {
const ReferrerLoadingState();
#override
List<Object> get props => [];
}
class ReferrerLoadedState extends ReferrerState {
const ReferrerLoadedState({required this.listReferrer});
final List<ItemReferrer> listReferrer;
#override
List<Object> get props => [listReferrer];
}
My code here Hope everyone can help! Thank
My code here Hope everyone can help! Thank
bloc
import 'dart:async';
import 'package:bloc/bloc.dart';
import 'package:equatable/equatable.dart';
import 'package:helloapp/referrer/models/item_referrer.dart';
part 'referrer_event.dart';
part 'referrer_state.dart';
class ReferrerBloc extends Bloc<ReferrerEvent, ReferrerState> {
ReferrerBloc() : super(const ReferrerLoadingState()) {
on<ReferrerEvent>((event, emit) {
});
on<ReferrerLoadedEvent>((event, emit) {
final listUser = [
Item1,
......
];
emit(ReferrerLoadedState(listReferrer: listUser));
});
on<ReferrerSortEvent>((event, emit) {
print(event.flag);
final listUser = [
Item1,
........
];
final List<ItemReferrer> listResult = [];
if (event.flag == 0) {
listUser.forEach(listResult.add);
} else if (event.flag == 1) {
listUser.forEach((element) {
if (element.flag == 1) {
listResult.add(element);
}
});
}
emit(ReferrerLoadedState(listReferrer: listResult));
});
}
}

Answer 1

You can use TabBar instead of Column.
Here's the official link of Flutter: https://docs.flutter.dev/cookbook/design/tabs