先看图,没图说个J8

Provide是Google官方推出的状态管理模式。(Google的亲儿子)
github地址为:https://github.com/google/flutter-provide
使用步骤如下:
1.在pubspec.yaml添加依赖
provide: ^1.0.2
2.创建add.dart文件
import 'package:flutter/material.dart';
class Counter with ChangeNotifier{
int value = 0;
//内部方法
increment(){
value ++;
notifyListeners();
}
}
3.在main.dart中注册provide
import 'package:flutter_shop/provide/add.dart';
import 'package:provide/provide.dart';
void main() {
var counter = Counter();
providers
..provide(Provider<Counter>.value(counter));
runApp(ProviderNode(child: MyApp(), providers: providers));
}
3.界面具体调用如下:
import 'package:flutter/material.dart';
import 'package:provide/provide.dart';
import 'add.dart';
class Number extends StatelessWidget {
@override
Widget build(BuildContext context) {
return Container(
margin: EdgeInsets.only(top: 200),
child: Provide<Counter>(
builder:(context,child,counter){
return Text('${counter.value}');
}
)
);
}
}
class Button extends StatelessWidget {
@override
Widget build(BuildContext context) {
return Container(
child: RaisedButton(
onPressed: (){
Provide.value<Counter>(context).increment();
},
child: Text('递增'),),
);
}
}