Provider使用：
1.创建CounterModel（等同于get中GetController）
class CounterModel with ChangeNotifier {
int _counter = 0;
int get counter => _counter;
void increment() {
_counter++;
notifyListeners();
}
}
2.注册（相当于get中Get.put）
class MyApp extends StatelessWidget {
const MyApp({Key key}) : super(key: key);
@override
Widget build(BuildContext context) {
return MultiProvider(
providers: [ChangeNotifierProvider(create: (_) => CounterModel())],
child: MaterialApp(
home: MyHomePage(),
));
}
}
3.使用
class MyHomePage extends StatelessWidget {
const MyHomePage({Key key}) : super(key: key);
@override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
title: const Text('Provider'),
),
body: Center(
child: Column(
mainAxisSize: MainAxisSize.min,
mainAxisAlignment: MainAxisAlignment.center,
children: [
Text('${context.watch<CounterModel>().counter}')
]),
),
floatingActionButton: FloatingActionButton(
onPressed: () => context.read<CounterModel>().increment(),
child: const Icon(Icons.add),
),
);
}
}
