android-studio - 查找已停用小部件的祖先是不安全的)颤振
问题描述
这是我的初始屏幕,我提供了自动导航到另一个屏幕的未来方法,
class SplashScreen extends StatelessWidget {
@override
Widget build(BuildContext context) {
Provider.of<DataBaseProvider>(context).getAllEmployees();
Future.delayed(Duration(seconds: 2)).then((value) {
Navigator.of(context).pushReplacement(MaterialPageRoute(builder: (context) => ListViewEmployees()));
});
return Scaffold(
body: Container(
child: Center(
child: GestureDetector(
onTap: (){
Navigator.of(context).pushReplacement(MaterialPageRoute(builder: (context) => ListViewEmployees()));
},
child: Text(
'Hello!' ,
style: TextStyle(
color: Colors.deepPurple ,
fontSize: 18 ,
),
),
),
),
),
);
}
}
这是错误信息
E/flutter ( 8699): [ERROR:flutter/lib/ui/ui_dart_state.cc(166)] Unhandled Exception: Looking up a deactivated widget's ancestor is unsafe.
E/flutter ( 8699): At this point the state of the widget's element tree is no longer stable.
E/flutter ( 8699): To safely refer to a widget's ancestor in its dispose() method, save a reference to the ancestor by calling dependOnInheritedWidgetOfExactType() in the widget's didChangeDependencies() method.
E/flutter ( 8699): #0 Element._debugCheckStateIsActiveForAncestorLookup.<anonymous closure> (package:flutter/src/widgets/framework.dart:3825:9)
E/flutter ( 8699): #1 _Closure.call (dart:core-patch/function.dart)
E/flutter ( 8699): #2 Element._debugCheckStateIsActiveForAncestorLookup (package:flutter/src/widgets/framework.dart:3839:6)
E/flutter ( 8699): #3 Element.findAncestorStateOfType (package:flutter/src/widgets/framework.dart:3958:12)
E/flutter ( 8699): #4 Navigator.of (package:flutter/src/widgets/navigator.dart:2185:40)
E/flutter ( 8699): #5 SplashScreen.build.<anonymous closure> (package:gsg_sqlitedb/ui/splash_screen.dart:12:17)
E/flutter ( 8699): #6 _rootRunUnary (dart:async/zone.dart:1198:47)
E/flutter ( 8699): #7 _CustomZone.runUnary (dart:async/zone.dart:1100:19)
E/flutter ( 8699): #8 _FutureListener.handleValue (dart:async/future_impl.dart:143:18)
E/flutter ( 8699): #9 Future._propagateToListeners.handleValueCallback (dart:async/future_impl.dart:696:45)
E/flutter ( 8699): #10 Future._propagateToListeners (dart:async/future_impl.dart:725:32)
E/flutter ( 8699): #11 Future._complete (dart:async/future_impl.dart:519:7)
E/flutter ( 8699): #12 new Future.delayed.<anonymous closure> (dart:async/future.dart:322:16)
E/flutter ( 8699): #13 _rootRun (dart:async/zone.dart:1182:47)
E/flutter ( 8699): #14 _CustomZone.run (dart:async/zone.dart:1093:19)
E/flutter ( 8699): #15 _CustomZone.runGuarded (dart:async/zone.dart:997:7)
E/flutter ( 8699): #16 _CustomZone.bindCallbackGuarded.<anonymous closure> (dart:async/zone.dart:1037:23)
E/flutter ( 8699): #17 _rootRun (dart:async/zone.dart:1190:13)
E/flutter ( 8699): #18 _CustomZone.run (dart:async/zone.dart:1093:19)
E/flutter ( 8699): #19 _CustomZone.bindCallback.<anonymous closure> (dart:async/zone.dart:1021:23)
E/flutter ( 8699): #20 Timer._createTimer.<anonymous closure> (dart:async-patch/timer_patch.dart:18:15)
E/flutter ( 8699): #21 _Timer._runTimers (dart:isolate-patch/timer_impl.dart:397:19)
E/flutter ( 8699): #22 _Timer._handleMessage (dart:isolate-patch/timer_impl.dart:428:5)
E/flutter ( 8699): #23 _RawReceivePortImpl._handleMessage (dart:isolate-patch/isolate_patch.dart:168:12)
当我删除延迟的未来,并通过单击按钮进行导航时,错误消失
解决了 !!!!!!这里 使用 Future.delayed 时测试中断
解决方案
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