[TOC]
简化Provider写法
- 简化类型声明，类型的泛型只需声明一次
- 轻松查看provider的调用关系，使用find usages查看调用关系
- 轻量，声明没任何字段的的ProviderKey常量 即可使用
provider_key:
git:
url: git:https://github.com/LuckyJayce/provider_key.git
//--this difine-------
final _counterKey = ChangeNotifierProviderKey<Counter>();
class CounterPage extends StatelessWidget {
@override
Widget build(BuildContext context) {
return MultiProvider(
providers: [
//--this provider-------
_counterKey.provider((context) => Counter()),
],
child: PageContent(),
);
}
}
class PageContent extends StatelessWidget {
@override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
title: const Text('Example'),
),
body: Column(
children:[
Text('You have pushed the button this many times:'),
//--this consumer-------
_counterKey.consumer(
(context, counter, child) {
return Text(
'${counter.count}',
style: Theme.of(context).textTheme.headline4,
);
},
),
],
),
floatingActionButton: FloatingActionButton(
//--this read-------
onPressed: () => _counterKey.read(context).increment(),
tooltip: 'Increment',
child: const Icon(Icons.add),
),
);
}
}
class Counter with ChangeNotifier {
int _count = 0;
int get count => _count;
void increment() {
_count++;
notifyListeners();
}
}
final _counterKey = ChangeNotifierProviderKey<Counter>();
MultiProvider(
providers: [
_counterKey.provider((context) => Counter()),
],
child: PageContent(),
)
_counterKey.consumer(
(context, counter, child) {
return Text(
'${counter.count}',
style: Theme.of(context).textTheme.headline4,
);
},
),
对应原先Provider的Consumer
_counterKey.selector<bool>(builder: (context, result, child) {
return Text('$result')
}, selector: (context, value) {
return value.count % 2 == 0;
}),
对应原先Provider的Selector
Counter conter = _counterKey.read(context);
对应Provider原先的写法
Counter conter = Provider.of<Counter>(context, listen: false);
//或者
Counter counter = context.read<Counter>();
Counter conter = _counterKey.watch(context);
对应Provider原先的写法
Counter conter = Provider.of<Counter>(context);
//或者
Counter counter = context.watch<Counter>();
Consumer2
final _number1Key = ChangeNotifierProviderKey<Number1Notifier>();
final _number2Key = ChangeNotifierProviderKey<Number2Notifier>();
//Consumer2
ProviderKey2.build(_number1Key, _number2Key).consumer(
(context, value1, value2, child) {
return Text(
'result:${value1.number + value2.number}',
style: Theme.of(context)
.textTheme
.headline6
.copyWith(color: Colors.orange),
);
},
),
Consumer3
final _number1Key = ChangeNotifierProviderKey<Number1Notifier>();
final _number2Key = ChangeNotifierProviderKey<Number2Notifier>();
final _number3Key = ChangeNotifierProviderKey<Number3Notifier>();
ProviderKey3.build(_number1Key, _number2Key, _number3Key).consumer(
(context, value1, value2, value3, child) {
return Text(
'result:${value1.number + value2.number + value3.number}',
style: Theme
.of(context)
.textTheme
.headline6
.copyWith(color: Colors.orange),
);
},
)
Provider => ProviderKey
InheritedProvider => InheritedProviderKey
ListenableProvider => ListenableProviderKey
ChangeNotifierProvider => ChangeNotifierProviderKey
.....
-
ProxyProvider
ProxyProvider => ProxyProviderKey
ProxyProvider2 => ProxyProviderKey2
ProxyProvider3 => ProxyProviderKey3
ProxyProvider4 => ProxyProviderKey4
ProxyProvider5 => ProxyProviderKey5
-
ChangeNotifierProxyProvider
ChangeNotifierProxyProvider => ChangeNotifierProxyProviderKey
ChangeNotifierProxyProvider2 => ChangeNotifierProxyProviderKey2
ChangeNotifierProxyProvider3 => ChangeNotifierProxyProviderKey3
ChangeNotifierProxyProvider4 => ChangeNotifierProxyProviderKey4
ChangeNotifierProxyProvider5 => ChangeNotifierProxyProviderKey5
示例：ChangeNotifierProxyProviderKey2 用法 ，详细代码查看[calculator_page.dart][https://github.com/LuckyJayce/provider_key/blob/master/example/lib/pages/demos/calculator_page.dart]
class Number1Notifier extends ChangeNotifier {
int _number = 0;
set number(int number) {
_number = number;
notifyListeners();
}
get number => _number;
}
class Number2Notifier extends ChangeNotifier {
int _number = 0;
set number(int number) {
_number = number;
notifyListeners();
}
get number => _number;
}
class ResultNumberNotifier with ChangeNotifier {
int result = 0;
DateTime changeTime;
void setNumbers(int number, int number2) {
this.result = number + number2;
this.changeTime = DateTime.now();
notifyListeners();
}
}
定义ProviderKey
final _number1Key = ChangeNotifierProviderKey<Number1Notifier>();
final _number2Key = ChangeNotifierProviderKey<Number2Notifier>();
final _result2Key = ChangeNotifierProxyProviderKey2.build(
dependKey1: _number1Key,
dependKey2: _number2Key,
selfType: ProviderType<ResultNumberNotifier>());
provider()
MultiProvider(
providers: [
_number1Key.provider((context) => Number1Notifier()),
_number2Key.provider((context) => Number2Notifier()),
_result2Key.provider(
(context) => ResultNumberNotifier(),
(context, number1, number2, previous) =>
previous..setNumbers(number1.number, number2.number)),
],
child: PageContent(),
);
consumer()
Container(
child: _result2Key.consumer((context, value, child) {
return Text(
'result:${value.result} \n changeTime:${DateFormat('yyyy-MM-dd hh:mm:ss').format(value.changeTime)}',
textAlign: TextAlign.center,
style: Theme.of(context)
.textTheme
.headline6
.copyWith(color: Colors.orange),
);
}),
),