Provider is one of the most popular state management libraries in Flutter. It wraps InheritedWidget and provides an easy way to share data between widgets.
1. Define State
main.dart
import 'package:flutter/material.dart';
import 'package:provider/provider.dart';
class CounterState extends ChangeNotifier {
int count = 0;
updateCount() {
count++;
notifyListeners();
}
}
2. Provide State
main.dart
class CounterApp extends StatelessWidget {
const CounterApp({ Key? key }) : super(key: key);
@override
Widget build(BuildContext context) {
return ChangeNotifierProvider(
create: (context) => CounterState(),
child: const CountText(),
);
}
}
3. Read State
main.dart
class CountText extends StatelessWidget {
const CountText({ Key? key }) : super(key: key);
@override
Widget build(BuildContext context) {
var state = context.watch<CounterState>();
var state2 = Provider.of<CounterState>(context);
return Text('${state.count}');
}
}