关键代码
MultiProvider(
providers: [
ChangeNotifierProvider(create: (_)=>CounterModel())
],
child: XX,
);
Consumer<CounterModel>(builder: (context,counter,_){
return Text(counter.count.toString());
});
import 'package:flutter/foundation.dart';
class CounterModel with ChangeNotifier {
int _count = 0;
int get count => _count;
void increment(){
_count++;
notifyListeners();
}
}
import 'package:flutter/material.dart';
import 'package:provider/provider.dart';
import 'package:stream_demo/model/counter.dart';
import 'detail_page.dart';
class MyHomePage extends StatefulWidget {
const MyHomePage({super.key, required this.title});
final String title;
@override
State<MyHomePage> createState() => _MyHomePageState();
}
class _MyHomePageState extends State<MyHomePage> {
@override
Widget build(BuildContext context) {
return MultiProvider(
providers: [
ChangeNotifierProvider(create: (_)=>CounterModel())
],
child: Scaffold(
appBar: AppBar(
title: Text(widget.title),
),
body: Center(
child: Column(
mainAxisAlignment: MainAxisAlignment.center,
children: <Widget>[
OutlinedButton(
onPressed: () {
Navigator.push(context,
MaterialPageRoute(builder: (context) {
return const MyDetailPage(title: "我是详情页面");
}));
},
child: Text("详情页")),
const Text(
'You have pushed the button this many times:',
),
CountWidget(),
],
),
),
floatingActionButton: Consumer<CounterModel>(builder: (context,counter,_){
return FloatingActionButton(
key: const Key('increment_floatingActionButton'),
onPressed: () {
counter.increment();
},
tooltip: 'Increment',
child: const Icon(Icons.add),
);
},), // This trailing comma makes auto-formatting nicer for build methods.
),
);
}
}
class CountWidget extends StatelessWidget {
@override
Widget build(BuildContext context) {
return Consumer<CounterModel>(builder: (context,counter,_){
return Text(counter.count.toString());
});
}
}