TickerProviderStateMixin dispose 报错 #461
Comments
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能提供一个最小的demo么？ |
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https://github.com/bitterking/redex_sample @zjuwjf 麻烦大佬看一下，谢谢~~ |
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@bitterking 这个问题我好像遇到过 我之前的推断原因是: flutter执行了"错误"的生命周期导致的:initState->initState->dispose, 导致dispose的是最新的controller。 暂时的解决办法: void _initState(Action action, Context<XxxxxState> ctx) {
....
ctx.extra["closeAnimation"] = clone.controller;
...
}
void _dispose(Action action, Context<XxxxState> ctx) {
(ctx.extra["closeAnimation"] as AnimationController)?.dispose();
ctx.extra["closeAnimation"] = null;
} |
Fix TickerProviderMixin’s dispose bug #461
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感谢，复现了这个问题。 它是由于 flutter 不是最合理的实现导致的 @override
void dispose() {
assert(() {
if (_tickers != null) {
for (Ticker ticker in _tickers) {
if (ticker.isActive) {
throw FlutterError('$this was disposed with an active Ticker.\n'
'$runtimeType created a Ticker via its TickerProviderStateMixin, but at the time '
'dispose() was called on the mixin, that Ticker was still active. All Tickers must '
'be disposed before or after calling super.dispose(). Tickers used by AnimationControllers '
'should be disposed by calling dispose() on the AnimationController itself. '
'Otherwise, the ticker will leak.\n'
'The offending ticker was: ${ticker.toString(debugIncludeStack: true)}');
}
}
}
return true;
}());
super.dispose();
}mixin TickerProviderMixin<T> on Component<T> {
@override
_TickerProviderStfState<T> createState() => _TickerProviderStfState<T>();
}
class _TickerProviderStfState<T> extends ComponentState<T>
with TickerProviderStateMixin {}当 Page mixin TickerProviderMixin 后 class WelcomePage extends Page<WelcomeState, Map<String, dynamic>>
with TickerProviderMixin<WelcomeState> {}当执行到dispose 所以还没进入我们的 void _dispose(Action action, Context<WelcomeState> ctx) {
ctx.state.controller.dispose();
}前，就先assert报错了。 合理的应该Flutter 应该这个做 @override
void dispose() {
super.dispose();
assert(() {
if (_tickers != null) {
for (Ticker ticker in _tickers) {
if (ticker.isActive) {
throw FlutterError('$this was disposed with an active Ticker.\n'
'$runtimeType created a Ticker via its TickerProviderStateMixin, but at the time '
'dispose() was called on the mixin, that Ticker was still active. All Tickers must '
'be disposed before or after calling super.dispose(). Tickers used by AnimationControllers '
'should be disposed by calling dispose() on the AnimationController itself. '
'Otherwise, the ticker will leak.\n'
'The offending ticker was: ${ticker.toString(debugIncludeStack: true)}');
}
}
}
return true;
}());
}目前fish-redux 内部处理了这个case。 下周一会在0.2.6中发布。 目前可以依赖master分支。 |
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@MMMzq @bitterking 你们的问题解决了么？ |
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我也是遇到了同样的问题 |
你说的问题，我并没有复现, 不断下拉刷新，执行一切符合预期。 initState 两次 是因为有两个item。 我的环境：flutter v1.9.1-hotfixes |
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我的版本信息:
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@MMMzq 非常感谢你提供的这个case。 为什么通过 会dispose最新的controller， 而非想要的dispose那份老的controller。 而通过 是正确的。 这引导我们去思考一个问题🤔： 状态的生命周期问题。 ctx.state 是一个函数，它总会根据固定的方法（connector）去获取自己最新的状态。在绝大多数场景（slots）下，它work的很好，但是在DynamicFlowAdapter场景下，情况会变的复杂。 一般而言，我们都说，组件是有生命周期的，状态是无生命周期的。 但是在@MMMzq 的case中，列表中的每一项状态，都是需要有生命周期的。 DynamicFlowAdapter的列表下 上面 @MMMzq 提到的问题就是，当为每一个组件设置一个唯一Key的时候，也就是每一个组件都不复用，那如何让刷新前的第1项的组件获得的state是刷新前的state，而让刷新后的第1项的组件获得的state是刷新后的state，尽管他们都是通过index来获取状态的。 再考虑这样的场景，当List下的某一个Item组件，发出一个action，被自己的reducer所处理，如何让列表下的组件合理的获取自己最新的state？ 再考虑一个场景，当List 被插入一行数据的时候，状态和widget又是如何在被复用的？ 下面解释下这个过程： /// Define itemBean how to get state with connector
///
/// [_isSimilar] return true just use newState after reducer safely
/// [_isSimilar] return false we should use cache state before reducer invoke.
/// for reducer change state immediately but sub component will refresh on next
/// frame. in this time the sub component will use cache state.
Get<Object> _subGetter(Get<List<ItemBean>> getter, int index) {
final List<ItemBean> curState = getter();
final Object subCache = curState[index].data;
return () {
final List<ItemBean> newState = getter();
/// Either all sub-components use cache or not.
if (_isSimilar(curState, newState)) {
return newState[index].data;
} else {
return subCache;
}
};
}
/// Judge [oldList] and [newList] is similar
///
/// if true: means the list size and every itemBean type & data.runtimeType
/// is equal.
bool _isSimilar(
List<ItemBean> oldList,
List<ItemBean> newList,
) {
if (oldList != newList &&
oldList?.length == newList.length &&
Collections.isNotEmpty(newList)) {
bool isEvery = true;
for (int i = 0; i < newList.length; i++) {
if (oldList[i].type != newList[i].type ||
oldList[i].data.runtimeType != newList[i].data.runtimeType) {
isEvery = false;
break;
}
}
return isEvery;
}
return false;
}
最新的 /// Define itemBean how to get state with connector
///
/// [_isSimilar] return true just use newState after reducer safely
/// [_isSimilar] return false we should use cache state before reducer invoke.
/// for reducer change state immediately but sub component will refresh on next
/// frame. in this time the sub component will use cache state.
Get<Object> _subGetter(Get<List<ItemBean>> getter, int index) {
final List<ItemBean> curState = getter();
ItemBean cacheItem = curState[index];
return () {
final List<ItemBean> newState = getter();
/// Either all sub-components use cache or not.
if (newState != null && newState.length > index) {
final ItemBean newItem = newState[index];
if (_couldReuse(cacheItem, newItem)) {
cacheItem = newItem;
}
}
return cacheItem.data;
};
}
bool _couldReuse(ItemBean beanA, ItemBean beanB) {
if (beanA.type != beanB.type) {
return false;
}
final Object dataA = beanA.data;
final Object dataB = beanB.data;
if (dataA.runtimeType != dataB.runtimeType) {
return false;
}
final Object keyA = dataA is StateKey ? dataA.key() : null;
final Object keyB = dataB is StateKey ? dataB.key() : null;
return keyA == keyB;
}修改后， Item状态的获取是否是最新的state，还是沿用上一份state， 完全取决于组件是否被复用，和ListView 下 Widget的复用机制吻合。 同时将Key的表达，推荐，迁移到State中来，让框架能感知到它。 class SuperItemState implements Cloneable<SuperItemState>, StateKey {
AnimationController controller;
Animation<Color> animationColor;
UniqueKey uniqueKey = UniqueKey();
SuperItemState();
@override
SuperItemState clone() {
return SuperItemState()
..controller = controller
..animationColor = animationColor
..uniqueKey = uniqueKey;
}
@override
Object key() {
return uniqueKey;
}
}
/// 同时不在需要在Component组合中提供 key
class SuperItemComponent extends Component<SuperItemState>
with
PrivateReducerMixin<SuperItemState>,
TickerProviderMixin<SuperItemState> {
SuperItemComponent()
: super(
effect: buildEffect(),
reducer: buildReducer(),
view: buildView,
// key: (state) => state.key(),
);
} |
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非常感谢,问题解决了😀. 但是我还有一个问题就是:为什么现在还是 |
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这个是flutter内部的处理流程， 从我理解，比较符合预期，先创建再释放。 一个listview下有2个item initState item0 |
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@zjuwjf 请问一下什么时候可以把这个改动发版？ |
在Lifecycle.dispose 中将正在执行的animationController dispose掉，会报错
感觉TickerProviderStateMixin 的dispose会先于ComponentState 中的dispose执行
`Effect buildEffect() {
return combineEffects(<Object, Effect>{
Lifecycle.initState: _init,
Lifecycle.dispose: _dispose,
SeatsAction.volumeChanged: _onVolumeChanged,
SeatsAction.selfVolumeChanged: _onSelfVolumeChanged,
});
}
void _init(Action action, Context ctx) {
final Object tickerProvider = ctx.stfState;
ctx.state.volumeAnimationControllers = List.generate(8, (index) {
return AnimationController(
duration: Duration(milliseconds: 1000), vsync: tickerProvider);
});
}
void _dispose(Action action, Context ctx) {
ctx.state.volumeAnimationControllers.forEach((controller) {
controller.dispose();
});
}`
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