I can’t save the state or data after stopping the application, which is the issue. Even after I close the app, I want it to retain my previous data or state. In what way can I accomplish that?
For state management, I am using Flutter Bloc. For your better understanding, below is my dummy code. Here, even after I close the application, I want to preserve the current state. However, I’m unable to get back the info or current state that I was browsing before I close the program.
import 'package:flutter/material.dart';
import 'package:flutter_bloc/flutter_bloc.dart';
import 'package:shared_preferences/shared_preferences.dart';
void main() {
runApp(MyApp());
}
class MyApp extends StatelessWidget {
@override
Widget build(BuildContext context) {
return MaterialApp(
title: 'Flutter Demo',
theme: ThemeData(
primarySwatch: Colors.blue,
),
home: BlocProvider(
create: (context) => LocationBloc(),
child: HomeScreen(),
),
);
}
}
class LocationBloc extends Bloc<LocationEvent, LocationState> {
LocationBloc() : super(null);
@override
Stream<LocationState> mapEventToState(LocationEvent event) async* {
switch (event) {
case LocationEvent.selectGPS:
yield GPSState();
break;
case LocationEvent.selectLocation:
yield LocationState();
break;
}
}
}
class GPSState extends LocationState {}
class LocationState extends LocationState {}
class HomeScreen extends StatelessWidget {
@override
Widget build(BuildContext context) {
final LocationBloc _locationBloc = BlocProvider.of<LocationBloc>(context);
return Scaffold(
appBar: AppBar(
title: Text('Home'),
),
body: BlocBuilder<LocationBloc, LocationState>(
builder: (context, state) {
return Center(
child: Text(
state.runtimeType == GPSState ? 'GPS' : 'Location',
style: TextStyle(fontSize: 24),
),
);
},
),
floatingActionButton: FloatingActionButton(
onPressed: () {
Navigator.push(
context,
MaterialPageRoute(builder: (context) => SettingsScreen()),
);
},
child: Icon(Icons.settings),
),
);
}
}
class SettingsScreen extends StatelessWidget {
@override
Widget build(BuildContext context) {
final LocationBloc _locationBloc = BlocProvider.of<LocationBloc>(context);
return Scaffold(
appBar: AppBar(
title: Text('Settings'),
),
body: BlocBuilder<LocationBloc, LocationState>(
builder: (context, state) {
return Column(
children: [
RadioListTile(
title: Text('GPS'),
value: GPSState(),
groupValue: state,
onChanged: (value) {
_locationBloc.add(LocationEvent.selectGPS);
},
),
RadioListTile(
title: Text('Location'),
value: LocationState(),
groupValue: state,
onChanged: (value) {
_locationBloc.add(LocationEvent.selectLocation);
},
),
],
);
},
),
);
}
}