在tabbar的页面之间配置State
Disposing State between the pages of tabbar
我正在开发一个应用程序，它包含一个计时器，因此它每秒更新一次状态，但是当我们更改页面时，会发生一些状态错误
This error happens if you call setState() on a State object for a widget that no longer appears in the widget tree (e.g., whose parent widget no longer includes the widget in its build). This error can occur when code
calls setState() from a timer or an animation callback. The preferred solution is to cancel the timer or stop listening to the animation in the dispose() callback. Another solution is to check the "mounted" property of this object before calling setState() to ensure the object is still in the tree.
E/flutter ( 5287): This error might indicate a memory leak if
setState() is being called because another object is retaining a
reference to this State object after it has been removed from the
tree. To avoid memory leaks, consider breaking the reference to this
object during dispose().
我真的不知道如何以及在哪里使用 dispose() 方法
错误示例
Example
所以请帮我处理之前的widget树，然后在我们切换屏幕时重建它。
我的代码可以分成两部分。包含所有内容的一个主页和触发设置状态的两个计时器部分。
第一部分：
import 'package:flutter/material.dart';
import '../Theme.dart' as Theme;
import '../Components/ropSayac.dart';
import '../Components/Stackvideostile.dart';
class Ropo extends StatefulWidget {
final RopoState state = new RopoState();
void update(bool exp) {
state.change(exp);
}
RopoState createState() => state;
}
class RopoState extends State<Ropo> {
bool videomounted, expired;
int remday = 0, remhour = 0, remmin = 0, remsec = 0;
void change(bool exp) {
setState(() {
this.expired = exp;
});
}
Widget updatetimer(int rday, rhour, rmin, rsec) {
setState(() {
remday = rday;
remhour = rhour;
remmin = rmin;
remsec = rsec;
});
}
Widget sayac(BuildContext context) {
return Container(
color: Colors.black,
height: 40.0,
width: MediaQuery.of(context).size.width,
child: new Container(
margin: EdgeInsets.only(left: 15.0, right: 15.0),
child: new Row(
// mainAxisAlignment: MainAxisAlignment.center,
crossAxisAlignment: CrossAxisAlignment.center,
children: <Widget>[
new Text(
"BU HAFTAKİ RÖPORTAJA",
style: Theme.TextStyles.ropsayacc,
),
new Expanded(
flex: 1,
child: new Container(
color: Colors.black,
),
),
new Text(
"$remday : $remhour : $remmin : $remsec",
style: Theme.TextStyles.ropsayaccint,
),
],
),
),
);
}
Widget konukyazi() {
// BU HAFTAKİ KONUĞUMUZ
return new Column(
crossAxisAlignment: CrossAxisAlignment.center,
children: <Widget>[
new Text(
"BU HAFTAKİ",
style: Theme.TextStyles.koseice,
),
new Text(
"KONUĞUMUZ",
style: Theme.TextStyles.koseice,
),
],
);
}
Widget konuk(String ad, var img) {
// Yuvarlak Şeklindeki Karakter Fotoğğğğğğrafı ve Çerçevesi
return new Container(
child: new Column(
children: <Widget>[
Stack(
alignment: Alignment.center,
children: <Widget>[
Container(
width: 226.0,
height: 226.0,
decoration: new BoxDecoration(
shape: BoxShape.circle, color: Theme.Colors.pagebackground),
),
Container(
width: 215.0,
height: 215.0,
decoration: new BoxDecoration(
shape: BoxShape.circle,
image: DecorationImage(
image: new AssetImage(img),
),
),
),
],
),
new Container(
height: 12.0,
),
new Text(
ad,
style: Theme.TextStyles.kosebas,
),
],
),
);
}
void initState() {
super.initState();
}
Widget updateexpired(bool expiredd) {
setState(() {
expired = expiredd;
});
}
Widget didvideomounted() {
if (expired == true) {
return new Text("video");
} else
return new Container(
width: 226.0,
height: 226.0,
decoration: new BoxDecoration(
shape: BoxShape.circle,
border: new Border.all(
width: 5.0, color: Theme.Colors.roportajheroborder)),
);
}
Widget rendervideoorui() {
if (expired == false) {
return new Column(
children: <Widget>[
Container(
height: 8.0,
),
konukyazi(),
Container(
height: 60.0,
),
konuk("Ayşe Alan", "assets/ayseAlan.png"),
],
);
} else {
return new Text("Video Geldi :D");
// return video
}
}
Widget stackvideos() {
return new Container(
decoration: new BoxDecoration(
color: Theme.Colors.tabbarbackground,
borderRadius: BorderRadius.all(Radius.circular(8.0)),
),
margin: EdgeInsets.only(top: 40.0, bottom: 10.0),
width: 358.0,
height: 343.0,
child: Column(
children: <Widget>[
Container(
// Üstteki bar
width: 358.0,
height: 46.0,
decoration: new BoxDecoration(
color: Theme.Colors.stackvideostopbar,
borderRadius: BorderRadius.all(Radius.circular(8.0)),
boxShadow: <BoxShadow>[
new BoxShadow(
color: Colors.black12,
blurRadius: 3.0,
offset: new Offset(0.0, 7.0),
),
],
),
child: Center(
child: new Text(
"BENCE Bİ’ ÖNCEKİLERE DE GÖZ AT",
style: Theme.TextStyles.stackvideotitle,
),
),
), //üstteki bar bitti
],
),
);
}
List<String> lists = ["asdas", "adadsa"];
@override
Widget build(BuildContext context) {
return Container(
color: Theme.Colors.pagebackground,
child: new Stack(
children: <Widget>[
new Container(
margin: EdgeInsets.only(left: 0.0, top: 37.0),
child: Image.asset(
"assets/k@3x.png",
// fit: BoxFit.fill,
),
),
new Container(
child: new Column(
children: <Widget>[
RopSayac(this),
new Expanded(
child: CustomScrollView(
slivers: <Widget>[
SliverToBoxAdapter(
child: new Column(
children: <Widget>[
rendervideoorui(),
new Container(height: 40.0,),
stackvideos(),
],
),
),
],
),
),
],
),
),
//new Image.asset("name"),
],
),
);
}
}
第二部分：
import 'package:flutter/material.dart';
import '../Pages/ropor.dart';
import '../Theme.dart' as Theme;
import 'dart:async';
class RopComponent extends StatelessWidget {
@override
Widget build(BuildContext context) {
return null;
}
}
class RopSayac extends StatefulWidget {
RopoState parent;
RopSayac(this.parent);
_RopSayacState createState() => _RopSayacState(parent);
}
class _RopSayacState extends State<RopSayac> {
RopoState parent;
_RopSayacState(this.parent);
int remday = 0, remhour = 0, remmin = 0, remsec = 0;
bool expired = false;
var _now = DateTime.now();
var endpoint = DateTime.parse("2019-01-24 11:23:30");
Timer _everySecond;
final Ropo ropo = new Ropo();
Widget sayac(
BuildContext context,
) {
return Container(
color: Colors.black,
height: 40.0,
width: MediaQuery.of(context).size.width,
child: new Container(
margin: EdgeInsets.only(left: 15.0, right: 15.0),
child: new Row(
// mainAxisAlignment: MainAxisAlignment.center,
crossAxisAlignment: CrossAxisAlignment.center,
children: <Widget>[
new Text(
"BU HAFTAKİ RÖPORTAJA",
style: Theme.TextStyles.ropsayacc,
),
new Expanded(
flex: 1,
child: new Container(
color: Colors.black,
),
),
new Text(
"$remday : $remhour : $remmin : $remsec",
style: Theme.TextStyles.ropsayaccint,
),
],
),
),
);
}
@override
void initState() {
super.initState();
// RopoState bilge = new RopoState();
// eğer videonun çıkacağı tarihten öndeysek
//sayacı başlat
_everySecond = Timer.periodic(Duration(seconds: 1), (Timer t) {
if (_now.isBefore(endpoint) == true ||
_now.difference(endpoint).inSeconds == 0) {
// bilge.updateexpired(false);
expired = false;
if (this.parent.mounted) {
this.parent.setState(() {
this.parent.expired = false;
});
}
// debugPrint(_now.toString());
_now = DateTime.now();
var remai = endpoint.difference(_now);
/// bilge.updatetimer(int.parse(remai.inDays.toString()), int.parse(remai.inHours.toString()) % 24, int.parse(remai.inMinutes.toString()) % 60, int.parse(remai.inSeconds.toString()) % 60);
if (this.mounted) {
setState(() {
_now = DateTime.now();
var remai = endpoint.difference(_now);
remday = int.parse(remai.inDays.toString());
remhour = int.parse(remai.inHours.toString()) % 24;
remmin = int.parse(remai.inMinutes.toString()) % 60;
remsec = int.parse(remai.inSeconds.toString()) % 60;
});
}
} else {
debugPrint("expired");
if (this.parent.mounted) {
this.parent.setState(() {
this.parent.expired = true;
});
}
// bilge.updateexpired(false);
}
});
}
// defines a timer
@override
Widget build(BuildContext context) {
return Container(
child: sayac(context),
);
}
}
完整错误日志：
For a more detailed help message, press "h". To detach, press "d"; to quit, press "q".
I/flutter ( 5287): ══╡ EXCEPTION CAUGHT BY WIDGETS LIBRARY ╞═══════════════════════════════════════════════════════════
I/flutter ( 5287): The following assertion was thrown building NotificationListener<KeepAliveNotification>:
I/flutter ( 5287): 'package:flutter/src/widgets/framework.dart': Failed assertion: line 3803 pos 12: '_state._widget ==
I/flutter ( 5287): null': is not true.
I/flutter ( 5287):
I/flutter ( 5287): Either the assertion indicates an error in the framework itself, or we should provide substantially
I/flutter ( 5287): more information in this error message to help you determine and fix the underlying cause.
I/flutter ( 5287): In either case, please report this assertion by filing a bug on GitHub:
I/flutter ( 5287): https://github.com/flutter/flutter/issues/new?template=BUG.md
I/flutter ( 5287):
I/flutter ( 5287): When the exception was thrown, this was the stack:
I/flutter ( 5287): #2 new StatefulElement (package:flutter/src/widgets/framework.dart:3803:12)
I/flutter ( 5287): #3 StatefulWidget.createElement (package:flutter/src/widgets/framework.dart:795:38)
I/flutter ( 5287): #4 Element.inflateWidget (package:flutter/src/widgets/framework.dart:2948:40)
I/flutter ( 5287): #5 Element.updateChild (package:flutter/src/widgets/framework.dart:2753:12)
I/flutter ( 5287): #6 SingleChildRenderObjectElement.mount (package:flutter/src/widgets/framework.dart:4860:14)
I/flutter ( 5287): #7 Element.inflateWidget (package:flutter/src/widgets/framework.dart:2950:14)
I/flutter ( 5287): #8 Element.updateChild (package:flutter/src/widgets/framework.dart:2753:12)
I/flutter ( 5287): #9 SingleChildRenderObjectElement.mount (package:flutter/src/widgets/framework.dart:4860:14)
I/flutter ( 5287): #10 Element.inflateWidget (package:flutter/src/widgets/framework.dart:2950:14)
I/flutter ( 5287): #11 Element.updateChild (package:flutter/src/widgets/framework.dart:2753:12)
I/flutter ( 5287): #12 ComponentElement.performRebuild (package:flutter/src/widgets/framework.dart:3732:16)
I/flutter ( 5287): #13 Element.rebuild (package:flutter/src/widgets/framework.dart:3547:5)
I/flutter ( 5287): #14 ComponentElement._firstBuild (package:flutter/src/widgets/framework.dart:3701:5)
I/flutter ( 5287): #15 ComponentElement.mount (package:flutter/src/widgets/framework.dart:3696:5)
I/flutter ( 5287): #16 Element.inflateWidget (package:flutter/src/widgets/framework.dart:2950:14)
I/flutter ( 5287): #17 Element.updateChild (package:flutter/src/widgets/framework.dart:2753:12)
I/flutter ( 5287): #18 ComponentElement.performRebuild (package:flutter/src/widgets/framework.dart:3732:16)
I/flutter ( 5287): #19 Element.rebuild (package:flutter/src/widgets/framework.dart:3547:5)
I/flutter ( 5287): #20 ComponentElement._firstBuild (package:flutter/src/widgets/framework.dart:3701:5)
I/flutter ( 5287): #21 ComponentElement.mount (package:flutter/src/widgets/framework.dart:3696:5)
I/flutter ( 5287): #22 ParentDataElement.mount (package:flutter/src/widgets/framework.dart:4047:11)
I/flutter ( 5287): #23 Element.inflateWidget (package:flutter/src/widgets/framework.dart:2950:14)
I/flutter ( 5287): #24 Element.updateChild (package:flutter/src/widgets/framework.dart:2753:12)
I/flutter ( 5287): #25 ComponentElement.performRebuild (package:flutter/src/widgets/framework.dart:3732:16)
I/flutter ( 5287): #26 Element.rebuild (package:flutter/src/widgets/framework.dart:3547:5)
I/flutter ( 5287): #27 ComponentElement._firstBuild (package:flutter/src/widgets/framework.dart:3701:5)
I/flutter ( 5287): #28 StatefulElement._firstBuild (package:flutter/src/widgets/framework.dart:3848:11)
I/flutter ( 5287): #29 ComponentElement.mount (package:flutter/src/widgets/framework.dart:3696:5)
I/flutter ( 5287): #30 Element.inflateWidget (package:flutter/src/widgets/framework.dart:2950:14)
I/flutter ( 5287): #31 Element.updateChild (package:flutter/src/widgets/framework.dart:2753:12)
I/flutter ( 5287): #32 SliverMultiBoxAdaptorElement.updateChild (package:flutter/src/widgets/sliver.dart:1028:36)
I/flutter ( 5287): #33 SliverMultiBoxAdaptorElement.createChild.<anonymous closure> (package:flutter/src/widgets/sliver.dart:1013:20)
I/flutter ( 5287): #34 BuildOwner.buildScope (package:flutter/src/widgets/framework.dart:2266:19)
I/flutter ( 5287): #35 SliverMultiBoxAdaptorElement.createChild (package:flutter/src/widgets/sliver.dart:1006:11)
I/flutter ( 5287): #36 RenderSliverMultiBoxAdaptor._createOrObtainChild.<anonymous closure> (package:flutter/src/rendering/sliver_multi_box_adaptor.dart:274:23)
I/flutter ( 5287): #37 RenderObject.invokeLayoutCallback.<anonymous closure> (package:flutter/src/rendering/object.dart:1730:58)
I/flutter ( 5287): #38 PipelineOwner._enableMutationsToDirtySubtrees (package:flutter/src/rendering/object.dart:799:15)
I/flutter ( 5287): #39 RenderObject.invokeLayoutCallback (package:flutter/src/rendering/object.dart:1730:13)
I/flutter ( 5287): #40 RenderSliverMultiBoxAdaptor._createOrObtainChild (package:flutter/src/rendering/sliver_multi_box_adaptor.dart:263:5)
I/flutter ( 5287): #41 RenderSliverMultiBoxAdaptor.insertAndLayoutLeadingChild (package:flutter/src/rendering/sliver_multi_box_adaptor.dart:372:5)
I/flutter ( 5287): #42 RenderSliverFixedExtentBoxAdaptor.performLayout (package:flutter/src/rendering/sliver_fixed_extent_list.dart:184:31)
I/flutter ( 5287): #43 RenderObject.layout (package:flutter/src/rendering/object.dart:1634:7)
I/flutter ( 5287): #44 RenderViewportBase.layoutChildSequence (package:flutter/src/rendering/viewport.dart:405:13)
I/flutter ( 5287): #45 RenderViewport._attemptLayout (package:flutter/src/rendering/viewport.dart:1316:12)
I/flutter ( 5287): #46 RenderViewport.performLayout (package:flutter/src/rendering/viewport.dart:1234:20)
I/flutter ( 5287): #47 RenderObject._layoutWithoutResize (package:flutter/src/rendering/object.dart:1509:7)
I/flutter ( 5287): #48 PipelineOwner.flushLayout (package:flutter/src/rendering/object.dart:768:18)
I/flutter ( 5287): #49 _WidgetsFlutterBinding&BindingBase&GestureBinding&ServicesBinding&SchedulerBinding&PaintingBinding&SemanticsBinding&RendererBinding.drawFrame (package:flutter/src/rendering/binding.dart:281:19)
I/flutter ( 5287): #50 _WidgetsFlutterBinding&BindingBase&GestureBinding&ServicesBinding&SchedulerBinding&PaintingBinding&SemanticsBinding&RendererBinding&WidgetsBinding.drawFrame (package:flutter/src/widgets/binding.dart:677:13)
I/flutter ( 5287): #51 _WidgetsFlutterBinding&BindingBase&GestureBinding&ServicesBinding&SchedulerBinding&PaintingBinding&SemanticsBinding&RendererBinding._handlePersistentFrameCallback (package:flutter/src/rendering/binding.dart:219:5)
I/flutter ( 5287): #52 _WidgetsFlutterBinding&BindingBase&GestureBinding&ServicesBinding&SchedulerBinding._invokeFrameCallback (package:flutter/src/scheduler/binding.dart:990:15)
I/flutter ( 5287): #53 _WidgetsFlutterBinding&BindingBase&GestureBinding&ServicesBinding&SchedulerBinding.handleDrawFrame (package:flutter/src/scheduler/binding.dart:930:9)
I/flutter ( 5287): #54 _WidgetsFlutterBinding&BindingBase&GestureBinding&ServicesBinding&SchedulerBinding._handleDrawFrame (package:flutter/src/scheduler/binding.dart:842:5)
I/flutter ( 5287): #55 _invoke (dart:ui/hooks.dart:154:13)
I/flutter ( 5287): #56 _drawFrame (dart:ui/hooks.dart:143:3)
I/flutter ( 5287): (elided 2 frames from class _AssertionError)
I/flutter ( 5287): ════════════════════════════════════════════════════════════════════════════════════════════════════
I/flutter ( 5287): Another exception was thrown: 'package:flutter/src/rendering/sliver_multi_box_adaptor.dart': Failed assertion: line 235 pos 16: 'indexOf(child) > index': is not true.
I/flutter ( 5287): Another exception was thrown: 'package:flutter/src/rendering/sliver_multi_box_adaptor.dart': Failed assertion: line 235 pos 16: 'indexOf(child) > index': is not true.
I/flutter ( 5287): Another exception was thrown: 'package:flutter/src/widgets/framework.dart': Failed assertion: line 2270 pos 20: '_debugCurrentBuildTarget == context': is not true.
I/flutter ( 5287): Another exception was thrown: 'package:flutter/src/rendering/sliver_multi_box_adaptor.dart': Failed assertion: line 461 pos 12: 'child.hasSize': is not true.
I/flutter ( 5287): Another exception was thrown: 'package:flutter/src/rendering/sliver_multi_box_adaptor.dart': Failed assertion: line 574 pos 16: 'indexOf(child) == index': is not true.
I/chatty ( 5287): uid=10086(com.example.aurorav10) 1.ui identical 2 lines
I/flutter ( 5287): Another exception was thrown: 'package:flutter/src/rendering/sliver_multi_box_adaptor.dart': Failed assertion: line 574 pos 16: 'indexOf(child) == index': is not true.
E/flutter ( 5287): [ERROR:flutter/shell/common/shell.cc(184)] Dart Error: Unhandled exception:
E/flutter ( 5287): setState() called after dispose(): RopoState#2b3f4(lifecycle state: defunct)
E/flutter ( 5287): This error happens if you call setState() on a State object for a widget that no longer appears in the widget tree (e.g., whose parent widget no longer includes the widget in its build). This error can occur when code
calls setState() from a timer or an animation callback. The preferred solution is to cancel the timer or stop listening to the animation in the dispose() callback. Another solution is to check the "mounted" property of this object before calling setState() to ensure the object is still in the tree.
E/flutter ( 5287): This error might indicate a memory leak if setState() is being called because another object is retaining a reference to this State object after it has been removed from the tree. To avoid memory leaks, consider breaking the reference to this object during dispose().
E/flutter ( 5287): #0 State.setState.<anonymous closure> (package:flutter/src/widgets/framework.dart:1103:9)
E/flutter ( 5287): #1 State.setState (package:flutter/src/widgets/framework.dart:1129:6)
E/flutter ( 5287): #2 _RopSayacState.initState.<anonymous closure> (package:aurorav10/Components/ropSayac.dart:111:23)
E/flutter ( 5287): #3 _Timer._runTimers (dart:isolate/runtime/libtimer_impl.dart:382:19)
E/flutter ( 5287): #4 _Timer._handleMessage (dart:isolate/runtime/libtimer_impl.dart:416:5)
E/flutter ( 5287): #5 _RawReceivePortImpl._handleMessage (dart:isolate/runtime/libisolate_patch.dart:171:12)
I/flutter ( 5287): Another exception was thrown: 'package:flutter/src/widgets/sliver.dart': Failed assertion: line 1008 pos 14: 'insertFirst || _childElements[index-1] != null': is not true.
I/chatty ( 5287): uid=10086(com.example.aurorav10) 1.ui identical 3 lines
I/flutter ( 5287): Another exception was thrown: 'package:flutter/src/widgets/sliver.dart': Failed assertion: line 1008 pos 14: 'insertFirst || _childElements[index-1] != null': is not true.
I/flutter ( 5287): Another exception was thrown: 'package:flutter/src/widgets/sliver.dart': Failed assertion: line 1053 pos 14: '_childElements.containsKey(index)': is not true.
I/chatty ( 5287): uid=10086(com.example.aurorav10) 1.ui identical 43 lines
I/flutter ( 5287): Another exception was thrown: 'package:flutter/src/widgets/sliver.dart': Failed assertion: line 1053 pos 14: '_childElements.containsKey(index)': is not true.
I/flutter ( 5287): Another exception was thrown: 'package:flutter/src/widgets/sliver.dart': Failed assertion: line 1008 pos 14: 'insertFirst || _childElements[index-1] != null': is not true.
I/chatty ( 5287): uid=10086(com.example.aurorav10) 1.ui identical 7 lines
I/flutter ( 5287): Another exception was thrown: 'package:flutter/src/widgets/sliver.dart': Failed assertion: line 1008 pos 14: 'insertFirst || _childElements[index-1] != null': is not true.
I/flutter ( 5287): Another exception was thrown: 'package:flutter/src/rendering/sliver_multi_box_adaptor.dart': Failed assertion: line 574 pos 16: 'indexOf(child) == index': is not true.
I/flutter ( 5287): Another exception was thrown: 'package:flutter/src/rendering/sliver_multi_box_adaptor.dart': Failed assertion: line 235 pos 16: 'indexOf(child) > index': is not true.
I/chatty ( 5287): uid=10086(com.example.aurorav10) 1.ui identical 1 line
I/flutter ( 5287): Another exception was thrown: 'package:flutter/src/rendering/sliver_multi_box_adaptor.dart': Failed assertion: line 235 pos 16: 'indexOf(child) > index': is not true.
I/flutter ( 5287): Another exception was thrown: 'package:flutter/src/widgets/framework.dart': Failed assertion: line 2270 pos 20: '_debugCurrentBuildTarget == context': is not true.
I/flutter ( 5287): Another exception was thrown: 'package:flutter/src/rendering/sliver_multi_box_adaptor.dart': Failed assertion: line 461 pos 12: 'child.hasSize': is not true.
I/flutter ( 5287): Another exception was thrown: 'package:flutter/src/rendering/sliver_multi_box_adaptor.dart': Failed assertion: line 574 pos 16: 'indexOf(child) == index': is not true.
I/chatty ( 5287): uid=10086(com.example.aurorav10) 1.ui identical 4 lines
I/flutter ( 5287): Another exception was thrown: 'package:flutter/src/rendering/sliver_multi_box_adaptor.dart': Failed assertion: line 574 pos 16: 'indexOf(child) == index': is not true.
I/flutter ( 5287): Another exception was thrown: 'package:flutter/src/widgets/sliver.dart': Failed assertion: line 1053 pos 14: '_childElements.containsKey(index)': is not true.
I/flutter ( 5287): Another exception was thrown: 'package:flutter/src/rendering/sliver_multi_box_adaptor.dart': Failed assertion: line 574 pos 16: 'indexOf(child) == index': is not true.
I/chatty ( 5287): uid=10086(com.example.aurorav10) 1.ui identical 6 lines
I/flutter ( 5287): Another exception was thrown: 'package:flutter/src/rendering/sliver_multi_box_adaptor.dart': Failed assertion: line 574 pos 16: 'indexOf(child) == index': is not true.
I/flutter ( 5287): Another exception was thrown: 'package:flutter/src/widgets/sliver.dart': Failed assertion: line 1053 pos 14: '_childElements.containsKey(index)': is not true.
I/chatty ( 5287): uid=10086(com.example.aurorav10) 1.ui identical 9 lines
I/flutter ( 5287): Another exception was thrown: 'package:flutter/src/widgets/sliver.dart': Failed assertion: line 1053 pos 14: '_childElements.containsKey(index)': is not true.
I/flutter ( 5287): Another exception was thrown: 'package:flutter/src/widgets/sliver.dart': Failed assertion: line 1053 pos 14: '_childElements.containsKey(index)': is not true.
I/chatty ( 5287): uid=10086(com.example.aurorav10) 1.ui identical 58 lines
I/flutter ( 5287): Another exception was thrown: 'package:flutter/src/widgets/sliver.dart': Failed assertion: line 1053 pos 14: '_childElements.containsKey(index)': is not true.
I/flutter ( 5287): Another exception was thrown: 'package:flutter/src/rendering/sliver_multi_box_adaptor.dart': Failed assertion: line 574 pos 16: 'indexOf(child) == index': is not true.
I/chatty ( 5287): uid=10086(com.example.aurorav10) 1.ui identical 6 lines
I/flutter ( 5287): Another exception was thrown: 'package:flutter/src/rendering/sliver_multi_box_adaptor.dart': Failed assertion: line 574 pos 16: 'indexOf(child) == index': is not true.
I/flutter ( 5287): Another exception was thrown: 'package:flutter/src/widgets/sliver.dart': Failed assertion: line 1053 pos 14: '_childElements.containsKey(index)': is not true.
谢谢
首先，请 trim 将您的代码归结为当您 post 提问时绝对必要的内容。那里有很多代码可以解析（尤其是因为它不是全英文的）。最起码，清理一下你的评论等等...
但手头的问题是您在 _RopSayacState 的 initState() 函数中创建了一个计时器，但之后一直没有停止它。正如您在问题中包含的错误所解释的那样，这会导致问题，因为当小部件不再可见时，它会从小部件树中删除，因此调用 setState 将导致错误。
要解决此问题，您只需在删除小部件时取消计时器即可。最简单的方法是覆盖 _RopSayacState 中的 dispose 方法。那应该是这样的。
@override
void dispose() {
_everySecond.cancel();
super.dispose();
}
我正在开发一个应用程序，它包含一个计时器，因此它每秒更新一次状态，但是当我们更改页面时，会发生一些状态错误
This error happens if you call setState() on a State object for a widget that no longer appears in the widget tree (e.g., whose parent widget no longer includes the widget in its build). This error can occur when code calls setState() from a timer or an animation callback. The preferred solution is to cancel the timer or stop listening to the animation in the dispose() callback. Another solution is to check the "mounted" property of this object before calling setState() to ensure the object is still in the tree.
E/flutter ( 5287): This error might indicate a memory leak if setState() is being called because another object is retaining a reference to this State object after it has been removed from the tree. To avoid memory leaks, consider breaking the reference to this object during dispose().
我真的不知道如何以及在哪里使用 dispose() 方法
错误示例 Example
所以请帮我处理之前的widget树，然后在我们切换屏幕时重建它。
我的代码可以分成两部分。包含所有内容的一个主页和触发设置状态的两个计时器部分。
第一部分：
import 'package:flutter/material.dart';
import '../Theme.dart' as Theme;
import '../Components/ropSayac.dart';
import '../Components/Stackvideostile.dart';
class Ropo extends StatefulWidget {
final RopoState state = new RopoState();
void update(bool exp) {
state.change(exp);
}
RopoState createState() => state;
}
class RopoState extends State<Ropo> {
bool videomounted, expired;
int remday = 0, remhour = 0, remmin = 0, remsec = 0;
void change(bool exp) {
setState(() {
this.expired = exp;
});
}
Widget updatetimer(int rday, rhour, rmin, rsec) {
setState(() {
remday = rday;
remhour = rhour;
remmin = rmin;
remsec = rsec;
});
}
Widget sayac(BuildContext context) {
return Container(
color: Colors.black,
height: 40.0,
width: MediaQuery.of(context).size.width,
child: new Container(
margin: EdgeInsets.only(left: 15.0, right: 15.0),
child: new Row(
// mainAxisAlignment: MainAxisAlignment.center,
crossAxisAlignment: CrossAxisAlignment.center,
children: <Widget>[
new Text(
"BU HAFTAKİ RÖPORTAJA",
style: Theme.TextStyles.ropsayacc,
),
new Expanded(
flex: 1,
child: new Container(
color: Colors.black,
),
),
new Text(
"$remday : $remhour : $remmin : $remsec",
style: Theme.TextStyles.ropsayaccint,
),
],
),
),
);
}
Widget konukyazi() {
// BU HAFTAKİ KONUĞUMUZ
return new Column(
crossAxisAlignment: CrossAxisAlignment.center,
children: <Widget>[
new Text(
"BU HAFTAKİ",
style: Theme.TextStyles.koseice,
),
new Text(
"KONUĞUMUZ",
style: Theme.TextStyles.koseice,
),
],
);
}
Widget konuk(String ad, var img) {
// Yuvarlak Şeklindeki Karakter Fotoğğğğğğrafı ve Çerçevesi
return new Container(
child: new Column(
children: <Widget>[
Stack(
alignment: Alignment.center,
children: <Widget>[
Container(
width: 226.0,
height: 226.0,
decoration: new BoxDecoration(
shape: BoxShape.circle, color: Theme.Colors.pagebackground),
),
Container(
width: 215.0,
height: 215.0,
decoration: new BoxDecoration(
shape: BoxShape.circle,
image: DecorationImage(
image: new AssetImage(img),
),
),
),
],
),
new Container(
height: 12.0,
),
new Text(
ad,
style: Theme.TextStyles.kosebas,
),
],
),
);
}
void initState() {
super.initState();
}
Widget updateexpired(bool expiredd) {
setState(() {
expired = expiredd;
});
}
Widget didvideomounted() {
if (expired == true) {
return new Text("video");
} else
return new Container(
width: 226.0,
height: 226.0,
decoration: new BoxDecoration(
shape: BoxShape.circle,
border: new Border.all(
width: 5.0, color: Theme.Colors.roportajheroborder)),
);
}
Widget rendervideoorui() {
if (expired == false) {
return new Column(
children: <Widget>[
Container(
height: 8.0,
),
konukyazi(),
Container(
height: 60.0,
),
konuk("Ayşe Alan", "assets/ayseAlan.png"),
],
);
} else {
return new Text("Video Geldi :D");
// return video
}
}
Widget stackvideos() {
return new Container(
decoration: new BoxDecoration(
color: Theme.Colors.tabbarbackground,
borderRadius: BorderRadius.all(Radius.circular(8.0)),
),
margin: EdgeInsets.only(top: 40.0, bottom: 10.0),
width: 358.0,
height: 343.0,
child: Column(
children: <Widget>[
Container(
// Üstteki bar
width: 358.0,
height: 46.0,
decoration: new BoxDecoration(
color: Theme.Colors.stackvideostopbar,
borderRadius: BorderRadius.all(Radius.circular(8.0)),
boxShadow: <BoxShadow>[
new BoxShadow(
color: Colors.black12,
blurRadius: 3.0,
offset: new Offset(0.0, 7.0),
),
],
),
child: Center(
child: new Text(
"BENCE Bİ’ ÖNCEKİLERE DE GÖZ AT",
style: Theme.TextStyles.stackvideotitle,
),
),
), //üstteki bar bitti
],
),
);
}
List<String> lists = ["asdas", "adadsa"];
@override
Widget build(BuildContext context) {
return Container(
color: Theme.Colors.pagebackground,
child: new Stack(
children: <Widget>[
new Container(
margin: EdgeInsets.only(left: 0.0, top: 37.0),
child: Image.asset(
"assets/k@3x.png",
// fit: BoxFit.fill,
),
),
new Container(
child: new Column(
children: <Widget>[
RopSayac(this),
new Expanded(
child: CustomScrollView(
slivers: <Widget>[
SliverToBoxAdapter(
child: new Column(
children: <Widget>[
rendervideoorui(),
new Container(height: 40.0,),
stackvideos(),
],
),
),
],
),
),
],
),
),
//new Image.asset("name"),
],
),
);
}
}
第二部分：
import 'package:flutter/material.dart';
import '../Pages/ropor.dart';
import '../Theme.dart' as Theme;
import 'dart:async';
class RopComponent extends StatelessWidget {
@override
Widget build(BuildContext context) {
return null;
}
}
class RopSayac extends StatefulWidget {
RopoState parent;
RopSayac(this.parent);
_RopSayacState createState() => _RopSayacState(parent);
}
class _RopSayacState extends State<RopSayac> {
RopoState parent;
_RopSayacState(this.parent);
int remday = 0, remhour = 0, remmin = 0, remsec = 0;
bool expired = false;
var _now = DateTime.now();
var endpoint = DateTime.parse("2019-01-24 11:23:30");
Timer _everySecond;
final Ropo ropo = new Ropo();
Widget sayac(
BuildContext context,
) {
return Container(
color: Colors.black,
height: 40.0,
width: MediaQuery.of(context).size.width,
child: new Container(
margin: EdgeInsets.only(left: 15.0, right: 15.0),
child: new Row(
// mainAxisAlignment: MainAxisAlignment.center,
crossAxisAlignment: CrossAxisAlignment.center,
children: <Widget>[
new Text(
"BU HAFTAKİ RÖPORTAJA",
style: Theme.TextStyles.ropsayacc,
),
new Expanded(
flex: 1,
child: new Container(
color: Colors.black,
),
),
new Text(
"$remday : $remhour : $remmin : $remsec",
style: Theme.TextStyles.ropsayaccint,
),
],
),
),
);
}
@override
void initState() {
super.initState();
// RopoState bilge = new RopoState();
// eğer videonun çıkacağı tarihten öndeysek
//sayacı başlat
_everySecond = Timer.periodic(Duration(seconds: 1), (Timer t) {
if (_now.isBefore(endpoint) == true ||
_now.difference(endpoint).inSeconds == 0) {
// bilge.updateexpired(false);
expired = false;
if (this.parent.mounted) {
this.parent.setState(() {
this.parent.expired = false;
});
}
// debugPrint(_now.toString());
_now = DateTime.now();
var remai = endpoint.difference(_now);
/// bilge.updatetimer(int.parse(remai.inDays.toString()), int.parse(remai.inHours.toString()) % 24, int.parse(remai.inMinutes.toString()) % 60, int.parse(remai.inSeconds.toString()) % 60);
if (this.mounted) {
setState(() {
_now = DateTime.now();
var remai = endpoint.difference(_now);
remday = int.parse(remai.inDays.toString());
remhour = int.parse(remai.inHours.toString()) % 24;
remmin = int.parse(remai.inMinutes.toString()) % 60;
remsec = int.parse(remai.inSeconds.toString()) % 60;
});
}
} else {
debugPrint("expired");
if (this.parent.mounted) {
this.parent.setState(() {
this.parent.expired = true;
});
}
// bilge.updateexpired(false);
}
});
}
// defines a timer
@override
Widget build(BuildContext context) {
return Container(
child: sayac(context),
);
}
}
完整错误日志：
For a more detailed help message, press "h". To detach, press "d"; to quit, press "q".
I/flutter ( 5287): ══╡ EXCEPTION CAUGHT BY WIDGETS LIBRARY ╞═══════════════════════════════════════════════════════════
I/flutter ( 5287): The following assertion was thrown building NotificationListener<KeepAliveNotification>:
I/flutter ( 5287): 'package:flutter/src/widgets/framework.dart': Failed assertion: line 3803 pos 12: '_state._widget ==
I/flutter ( 5287): null': is not true.
I/flutter ( 5287):
I/flutter ( 5287): Either the assertion indicates an error in the framework itself, or we should provide substantially
I/flutter ( 5287): more information in this error message to help you determine and fix the underlying cause.
I/flutter ( 5287): In either case, please report this assertion by filing a bug on GitHub:
I/flutter ( 5287): https://github.com/flutter/flutter/issues/new?template=BUG.md
I/flutter ( 5287):
I/flutter ( 5287): When the exception was thrown, this was the stack:
I/flutter ( 5287): #2 new StatefulElement (package:flutter/src/widgets/framework.dart:3803:12)
I/flutter ( 5287): #3 StatefulWidget.createElement (package:flutter/src/widgets/framework.dart:795:38)
I/flutter ( 5287): #4 Element.inflateWidget (package:flutter/src/widgets/framework.dart:2948:40)
I/flutter ( 5287): #5 Element.updateChild (package:flutter/src/widgets/framework.dart:2753:12)
I/flutter ( 5287): #6 SingleChildRenderObjectElement.mount (package:flutter/src/widgets/framework.dart:4860:14)
I/flutter ( 5287): #7 Element.inflateWidget (package:flutter/src/widgets/framework.dart:2950:14)
I/flutter ( 5287): #8 Element.updateChild (package:flutter/src/widgets/framework.dart:2753:12)
I/flutter ( 5287): #9 SingleChildRenderObjectElement.mount (package:flutter/src/widgets/framework.dart:4860:14)
I/flutter ( 5287): #10 Element.inflateWidget (package:flutter/src/widgets/framework.dart:2950:14)
I/flutter ( 5287): #11 Element.updateChild (package:flutter/src/widgets/framework.dart:2753:12)
I/flutter ( 5287): #12 ComponentElement.performRebuild (package:flutter/src/widgets/framework.dart:3732:16)
I/flutter ( 5287): #13 Element.rebuild (package:flutter/src/widgets/framework.dart:3547:5)
I/flutter ( 5287): #14 ComponentElement._firstBuild (package:flutter/src/widgets/framework.dart:3701:5)
I/flutter ( 5287): #15 ComponentElement.mount (package:flutter/src/widgets/framework.dart:3696:5)
I/flutter ( 5287): #16 Element.inflateWidget (package:flutter/src/widgets/framework.dart:2950:14)
I/flutter ( 5287): #17 Element.updateChild (package:flutter/src/widgets/framework.dart:2753:12)
I/flutter ( 5287): #18 ComponentElement.performRebuild (package:flutter/src/widgets/framework.dart:3732:16)
I/flutter ( 5287): #19 Element.rebuild (package:flutter/src/widgets/framework.dart:3547:5)
I/flutter ( 5287): #20 ComponentElement._firstBuild (package:flutter/src/widgets/framework.dart:3701:5)
I/flutter ( 5287): #21 ComponentElement.mount (package:flutter/src/widgets/framework.dart:3696:5)
I/flutter ( 5287): #22 ParentDataElement.mount (package:flutter/src/widgets/framework.dart:4047:11)
I/flutter ( 5287): #23 Element.inflateWidget (package:flutter/src/widgets/framework.dart:2950:14)
I/flutter ( 5287): #24 Element.updateChild (package:flutter/src/widgets/framework.dart:2753:12)
I/flutter ( 5287): #25 ComponentElement.performRebuild (package:flutter/src/widgets/framework.dart:3732:16)
I/flutter ( 5287): #26 Element.rebuild (package:flutter/src/widgets/framework.dart:3547:5)
I/flutter ( 5287): #27 ComponentElement._firstBuild (package:flutter/src/widgets/framework.dart:3701:5)
I/flutter ( 5287): #28 StatefulElement._firstBuild (package:flutter/src/widgets/framework.dart:3848:11)
I/flutter ( 5287): #29 ComponentElement.mount (package:flutter/src/widgets/framework.dart:3696:5)
I/flutter ( 5287): #30 Element.inflateWidget (package:flutter/src/widgets/framework.dart:2950:14)
I/flutter ( 5287): #31 Element.updateChild (package:flutter/src/widgets/framework.dart:2753:12)
I/flutter ( 5287): #32 SliverMultiBoxAdaptorElement.updateChild (package:flutter/src/widgets/sliver.dart:1028:36)
I/flutter ( 5287): #33 SliverMultiBoxAdaptorElement.createChild.<anonymous closure> (package:flutter/src/widgets/sliver.dart:1013:20)
I/flutter ( 5287): #34 BuildOwner.buildScope (package:flutter/src/widgets/framework.dart:2266:19)
I/flutter ( 5287): #35 SliverMultiBoxAdaptorElement.createChild (package:flutter/src/widgets/sliver.dart:1006:11)
I/flutter ( 5287): #36 RenderSliverMultiBoxAdaptor._createOrObtainChild.<anonymous closure> (package:flutter/src/rendering/sliver_multi_box_adaptor.dart:274:23)
I/flutter ( 5287): #37 RenderObject.invokeLayoutCallback.<anonymous closure> (package:flutter/src/rendering/object.dart:1730:58)
I/flutter ( 5287): #38 PipelineOwner._enableMutationsToDirtySubtrees (package:flutter/src/rendering/object.dart:799:15)
I/flutter ( 5287): #39 RenderObject.invokeLayoutCallback (package:flutter/src/rendering/object.dart:1730:13)
I/flutter ( 5287): #40 RenderSliverMultiBoxAdaptor._createOrObtainChild (package:flutter/src/rendering/sliver_multi_box_adaptor.dart:263:5)
I/flutter ( 5287): #41 RenderSliverMultiBoxAdaptor.insertAndLayoutLeadingChild (package:flutter/src/rendering/sliver_multi_box_adaptor.dart:372:5)
I/flutter ( 5287): #42 RenderSliverFixedExtentBoxAdaptor.performLayout (package:flutter/src/rendering/sliver_fixed_extent_list.dart:184:31)
I/flutter ( 5287): #43 RenderObject.layout (package:flutter/src/rendering/object.dart:1634:7)
I/flutter ( 5287): #44 RenderViewportBase.layoutChildSequence (package:flutter/src/rendering/viewport.dart:405:13)
I/flutter ( 5287): #45 RenderViewport._attemptLayout (package:flutter/src/rendering/viewport.dart:1316:12)
I/flutter ( 5287): #46 RenderViewport.performLayout (package:flutter/src/rendering/viewport.dart:1234:20)
I/flutter ( 5287): #47 RenderObject._layoutWithoutResize (package:flutter/src/rendering/object.dart:1509:7)
I/flutter ( 5287): #48 PipelineOwner.flushLayout (package:flutter/src/rendering/object.dart:768:18)
I/flutter ( 5287): #49 _WidgetsFlutterBinding&BindingBase&GestureBinding&ServicesBinding&SchedulerBinding&PaintingBinding&SemanticsBinding&RendererBinding.drawFrame (package:flutter/src/rendering/binding.dart:281:19)
I/flutter ( 5287): #50 _WidgetsFlutterBinding&BindingBase&GestureBinding&ServicesBinding&SchedulerBinding&PaintingBinding&SemanticsBinding&RendererBinding&WidgetsBinding.drawFrame (package:flutter/src/widgets/binding.dart:677:13)
I/flutter ( 5287): #51 _WidgetsFlutterBinding&BindingBase&GestureBinding&ServicesBinding&SchedulerBinding&PaintingBinding&SemanticsBinding&RendererBinding._handlePersistentFrameCallback (package:flutter/src/rendering/binding.dart:219:5)
I/flutter ( 5287): #52 _WidgetsFlutterBinding&BindingBase&GestureBinding&ServicesBinding&SchedulerBinding._invokeFrameCallback (package:flutter/src/scheduler/binding.dart:990:15)
I/flutter ( 5287): #53 _WidgetsFlutterBinding&BindingBase&GestureBinding&ServicesBinding&SchedulerBinding.handleDrawFrame (package:flutter/src/scheduler/binding.dart:930:9)
I/flutter ( 5287): #54 _WidgetsFlutterBinding&BindingBase&GestureBinding&ServicesBinding&SchedulerBinding._handleDrawFrame (package:flutter/src/scheduler/binding.dart:842:5)
I/flutter ( 5287): #55 _invoke (dart:ui/hooks.dart:154:13)
I/flutter ( 5287): #56 _drawFrame (dart:ui/hooks.dart:143:3)
I/flutter ( 5287): (elided 2 frames from class _AssertionError)
I/flutter ( 5287): ════════════════════════════════════════════════════════════════════════════════════════════════════
I/flutter ( 5287): Another exception was thrown: 'package:flutter/src/rendering/sliver_multi_box_adaptor.dart': Failed assertion: line 235 pos 16: 'indexOf(child) > index': is not true.
I/flutter ( 5287): Another exception was thrown: 'package:flutter/src/rendering/sliver_multi_box_adaptor.dart': Failed assertion: line 235 pos 16: 'indexOf(child) > index': is not true.
I/flutter ( 5287): Another exception was thrown: 'package:flutter/src/widgets/framework.dart': Failed assertion: line 2270 pos 20: '_debugCurrentBuildTarget == context': is not true.
I/flutter ( 5287): Another exception was thrown: 'package:flutter/src/rendering/sliver_multi_box_adaptor.dart': Failed assertion: line 461 pos 12: 'child.hasSize': is not true.
I/flutter ( 5287): Another exception was thrown: 'package:flutter/src/rendering/sliver_multi_box_adaptor.dart': Failed assertion: line 574 pos 16: 'indexOf(child) == index': is not true.
I/chatty ( 5287): uid=10086(com.example.aurorav10) 1.ui identical 2 lines
I/flutter ( 5287): Another exception was thrown: 'package:flutter/src/rendering/sliver_multi_box_adaptor.dart': Failed assertion: line 574 pos 16: 'indexOf(child) == index': is not true.
E/flutter ( 5287): [ERROR:flutter/shell/common/shell.cc(184)] Dart Error: Unhandled exception:
E/flutter ( 5287): setState() called after dispose(): RopoState#2b3f4(lifecycle state: defunct)
E/flutter ( 5287): This error happens if you call setState() on a State object for a widget that no longer appears in the widget tree (e.g., whose parent widget no longer includes the widget in its build). This error can occur when code
calls setState() from a timer or an animation callback. The preferred solution is to cancel the timer or stop listening to the animation in the dispose() callback. Another solution is to check the "mounted" property of this object before calling setState() to ensure the object is still in the tree.
E/flutter ( 5287): This error might indicate a memory leak if setState() is being called because another object is retaining a reference to this State object after it has been removed from the tree. To avoid memory leaks, consider breaking the reference to this object during dispose().
E/flutter ( 5287): #0 State.setState.<anonymous closure> (package:flutter/src/widgets/framework.dart:1103:9)
E/flutter ( 5287): #1 State.setState (package:flutter/src/widgets/framework.dart:1129:6)
E/flutter ( 5287): #2 _RopSayacState.initState.<anonymous closure> (package:aurorav10/Components/ropSayac.dart:111:23)
E/flutter ( 5287): #3 _Timer._runTimers (dart:isolate/runtime/libtimer_impl.dart:382:19)
E/flutter ( 5287): #4 _Timer._handleMessage (dart:isolate/runtime/libtimer_impl.dart:416:5)
E/flutter ( 5287): #5 _RawReceivePortImpl._handleMessage (dart:isolate/runtime/libisolate_patch.dart:171:12)
I/flutter ( 5287): Another exception was thrown: 'package:flutter/src/widgets/sliver.dart': Failed assertion: line 1008 pos 14: 'insertFirst || _childElements[index-1] != null': is not true.
I/chatty ( 5287): uid=10086(com.example.aurorav10) 1.ui identical 3 lines
I/flutter ( 5287): Another exception was thrown: 'package:flutter/src/widgets/sliver.dart': Failed assertion: line 1008 pos 14: 'insertFirst || _childElements[index-1] != null': is not true.
I/flutter ( 5287): Another exception was thrown: 'package:flutter/src/widgets/sliver.dart': Failed assertion: line 1053 pos 14: '_childElements.containsKey(index)': is not true.
I/chatty ( 5287): uid=10086(com.example.aurorav10) 1.ui identical 43 lines
I/flutter ( 5287): Another exception was thrown: 'package:flutter/src/widgets/sliver.dart': Failed assertion: line 1053 pos 14: '_childElements.containsKey(index)': is not true.
I/flutter ( 5287): Another exception was thrown: 'package:flutter/src/widgets/sliver.dart': Failed assertion: line 1008 pos 14: 'insertFirst || _childElements[index-1] != null': is not true.
I/chatty ( 5287): uid=10086(com.example.aurorav10) 1.ui identical 7 lines
I/flutter ( 5287): Another exception was thrown: 'package:flutter/src/widgets/sliver.dart': Failed assertion: line 1008 pos 14: 'insertFirst || _childElements[index-1] != null': is not true.
I/flutter ( 5287): Another exception was thrown: 'package:flutter/src/rendering/sliver_multi_box_adaptor.dart': Failed assertion: line 574 pos 16: 'indexOf(child) == index': is not true.
I/flutter ( 5287): Another exception was thrown: 'package:flutter/src/rendering/sliver_multi_box_adaptor.dart': Failed assertion: line 235 pos 16: 'indexOf(child) > index': is not true.
I/chatty ( 5287): uid=10086(com.example.aurorav10) 1.ui identical 1 line
I/flutter ( 5287): Another exception was thrown: 'package:flutter/src/rendering/sliver_multi_box_adaptor.dart': Failed assertion: line 235 pos 16: 'indexOf(child) > index': is not true.
I/flutter ( 5287): Another exception was thrown: 'package:flutter/src/widgets/framework.dart': Failed assertion: line 2270 pos 20: '_debugCurrentBuildTarget == context': is not true.
I/flutter ( 5287): Another exception was thrown: 'package:flutter/src/rendering/sliver_multi_box_adaptor.dart': Failed assertion: line 461 pos 12: 'child.hasSize': is not true.
I/flutter ( 5287): Another exception was thrown: 'package:flutter/src/rendering/sliver_multi_box_adaptor.dart': Failed assertion: line 574 pos 16: 'indexOf(child) == index': is not true.
I/chatty ( 5287): uid=10086(com.example.aurorav10) 1.ui identical 4 lines
I/flutter ( 5287): Another exception was thrown: 'package:flutter/src/rendering/sliver_multi_box_adaptor.dart': Failed assertion: line 574 pos 16: 'indexOf(child) == index': is not true.
I/flutter ( 5287): Another exception was thrown: 'package:flutter/src/widgets/sliver.dart': Failed assertion: line 1053 pos 14: '_childElements.containsKey(index)': is not true.
I/flutter ( 5287): Another exception was thrown: 'package:flutter/src/rendering/sliver_multi_box_adaptor.dart': Failed assertion: line 574 pos 16: 'indexOf(child) == index': is not true.
I/chatty ( 5287): uid=10086(com.example.aurorav10) 1.ui identical 6 lines
I/flutter ( 5287): Another exception was thrown: 'package:flutter/src/rendering/sliver_multi_box_adaptor.dart': Failed assertion: line 574 pos 16: 'indexOf(child) == index': is not true.
I/flutter ( 5287): Another exception was thrown: 'package:flutter/src/widgets/sliver.dart': Failed assertion: line 1053 pos 14: '_childElements.containsKey(index)': is not true.
I/chatty ( 5287): uid=10086(com.example.aurorav10) 1.ui identical 9 lines
I/flutter ( 5287): Another exception was thrown: 'package:flutter/src/widgets/sliver.dart': Failed assertion: line 1053 pos 14: '_childElements.containsKey(index)': is not true.
I/flutter ( 5287): Another exception was thrown: 'package:flutter/src/widgets/sliver.dart': Failed assertion: line 1053 pos 14: '_childElements.containsKey(index)': is not true.
I/chatty ( 5287): uid=10086(com.example.aurorav10) 1.ui identical 58 lines
I/flutter ( 5287): Another exception was thrown: 'package:flutter/src/widgets/sliver.dart': Failed assertion: line 1053 pos 14: '_childElements.containsKey(index)': is not true.
I/flutter ( 5287): Another exception was thrown: 'package:flutter/src/rendering/sliver_multi_box_adaptor.dart': Failed assertion: line 574 pos 16: 'indexOf(child) == index': is not true.
I/chatty ( 5287): uid=10086(com.example.aurorav10) 1.ui identical 6 lines
I/flutter ( 5287): Another exception was thrown: 'package:flutter/src/rendering/sliver_multi_box_adaptor.dart': Failed assertion: line 574 pos 16: 'indexOf(child) == index': is not true.
I/flutter ( 5287): Another exception was thrown: 'package:flutter/src/widgets/sliver.dart': Failed assertion: line 1053 pos 14: '_childElements.containsKey(index)': is not true.
谢谢
首先，请 trim 将您的代码归结为当您 post 提问时绝对必要的内容。那里有很多代码可以解析（尤其是因为它不是全英文的）。最起码，清理一下你的评论等等...
但手头的问题是您在 _RopSayacState 的 initState() 函数中创建了一个计时器，但之后一直没有停止它。正如您在问题中包含的错误所解释的那样，这会导致问题，因为当小部件不再可见时，它会从小部件树中删除，因此调用 setState 将导致错误。
要解决此问题，您只需在删除小部件时取消计时器即可。最简单的方法是覆盖 _RopSayacState 中的 dispose 方法。那应该是这样的。
@override
void dispose() {
_everySecond.cancel();
super.dispose();
}