A flutter package similar to Android's lifecycle.
给flutter添加了类似于Android生命周期的方法,其中LifecycleState
适用于普通页面,只要把我们用的State替换成LifecycleState即可,LifecycleInnerState
适用于PageView中的页面
lifecycle_state:
git:
url: "https://github.com/tianyu704/lifecycle_state.git"
or
lifecycle_state: ^0.0.1
import 'package:lifecycle_state/lifecycle_state.dart';
@override
Widget build(BuildContext context) {
return MaterialApp(
title: 'Test',
navigatorObservers: [routeObserver],
...
);
}
routeObserver 是在lifecycle_state中定义的
- 直接继承
LifecycleState
class TestPage extends StatefulWidget {
@override
State<StatefulWidget> createState() {
// TODO: implement createState
return _TestPageState();
}
}
class _TestPageState extends LifecycleState<TestPage> {
PageController _controller;
@override
void onCreate() {
// TODO: implement onCreate
super.onCreate();
_controller = PageController();
// log("onCreate");
}
@override
Widget build(BuildContext context) {
// TODO: implement buildWidget
return Scaffold(
body: PageView(
controller: _controller,
onPageChanged: (index) {
eventBus.fire(LifecycleInnerEvent(index, "tag"));
},
children: <Widget>[
ItemPage(0, "tag"),
ItemPage(1, "tag"),
ItemPage(2, "tag"),
],
),
floatingActionButton: FloatingActionButton(onPressed: () {
Navigator.of(context).push(MaterialPageRoute(builder: (context) {
return SecondPage();
}));
}),
);
}
@override
void onResume() {
// TODO: implement onResume
super.onResume();
log("onResume");
}
@override
void onPause() {
// TODO: implement onPause
super.onPause();
log("onPause");
}
@override
void onDestroy() {
// TODO: implement onDestroy
super.onDestroy();
log("onDestroy");
}
@override
void onLoadData() {
// TODO: implement onLoadData
super.onLoadData();
log("onLoadData");
}
@override
void onBackground() {
// TODO: implement onBackground
super.onBackground();
log("onBackground");
}
@override
void onForeground() {
// TODO: implement onForeground
super.onForeground();
log("onForeground");
}
}
- 如果要在PageView中使用,flutter默认每次切换page,旧的page是销毁的,如果你的页面可以这样就可以直接用LifecycleState,但如果你不想每次都销毁重建,就用
LifecycleInnerState
,但这个稍微麻烦的是得手动通知页面状态变化,这里暂时使用event_bus
通信,就是在PageView的onPageChanged中导包并调用eventBus.fire(LifecycleInnerEvent(index, "tag"));
,"tag"是用来标记每个pageview的,避免一个pageview改变,通知到别的pageview。LifecycleInnerState
中加入了AutomaticKeepAliveClientMixin
防止页面销毁,你自己的类中就不要加了
import 'package:schulte_grid_flutter/src/lifecycle_inner_state.dart';
...
PageView(
controller: _controller,
onPageChanged: (index) {
eventBus.fire(LifecycleInnerEvent(index, "tag"));
},
children: <Widget>[
ItemPage(0),
ItemPage(1),
ItemPage(2),
],
),
...
class ItemPage extends StatefulWidget {
final int index;
ItemPage(this.index);
@override
State<StatefulWidget> createState() {
// TODO: implement createState
return _ItemPageState();
}
}
class _ItemPageState extends LifecycleInnerState<ItemPage> {
@override
Widget build(BuildContext context) {
// TODO: implement build
return Scaffold(
body: Center(
child: Text("${widget.index}"),
),
);
}
@override
int setPosition() {
// TODO: implement setPosition
return widget.index;
}
@override
void onLoadData() {
// TODO: implement onLoadData
super.onLoadData();
log("onLoadData");
}
@override
void onResume() {
// TODO: implement onResume
super.onResume();
log("onResume");
}
@override
void onPause() {
// TODO: implement onPause
super.onPause();
log("onPause");
}
@override
void onDestroy() {
// TODO: implement onDestroy
super.onDestroy();
log("onDestroy");
}
@override
void onCreate() {
// TODO: implement onCreate
super.onCreate();
log("onCreate");
}
@override
// TODO: implement wa
// ntKeepAlive
bool get wantKeepAlive => true;
@override
String setTag() {
// TODO: implement setTag
return "tag";
}
}
参考:
- LifecycleState参考于 https://github.com/tinyvampirepudge/flutter_lifecycle_state ,但是他的这个我用着是有bug的,当跳转到继承原生State的页面中再回来时,方法调用会出错,有的生命周期方法会不调用了
- LifecycleInnerState参考于 https://github.com/385841539/flutter_BaseWidget 中的一部分,他这个有一个通用的页面生命周期的基类,采用一个map记录了所有页面,然后通过判断当前页面是栈顶或第二个来调用相应的生命周期方法,因此你必须所有页面都继承他的基类,如果跳转到不继承基类的页面中那么那些方法调用就是错误的
综合这两个的优缺点自己改了一个版本,在想用的时候就用LifecycleState
或fecycleInnerState
,不想用也没关系,不影响用的页面