尝试从列表中删除对象时在迭代过程中进行并发修改 [英] Concurrent modification during iteration while trying to remove object from a list
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问题描述
我试图循环多个列表,最后比较它们的名称,如果它们不匹配,则将其从列表中删除...
Am trying to loop in multiple lists and finally comparing their names and delete it from a list if they don't match ...
但出现此错误:
迭代期间的并发修改:
Concurrent modification during iteration:
尽管我为了避免该错误而复制了原始列表,但仍然得到它..我尝试的是:
although i have took a copy of the original list just to avoid this error .. but still am getting it .. what i tried is:
globals.filteredPollsList = pollsList;
pollsList.forEach( (p) {
for (var e in entitiesList) {
print(e.name);
for (var entity in entitiesFilter) {
print(entity);
print(e.name);
if (e.name != entity && p.entityId != e.id) {
print('true');
globals.filteredPollsList.remove(p);
}
}
}
});
但出现此错误:
flutter: ══╡ EXCEPTION CAUGHT BY GESTURE ╞═══════════════════════════════════════════════════════════════════
flutter: The following ConcurrentModificationError was thrown while handling a gesture:
flutter: Concurrent modification during iteration: Instance(length:8) of '_GrowableList'.
flutter:
flutter: When the exception was thrown, this was the stack:
flutter: #0 List.forEach (dart:core/runtime/libgrowable_array.dart:279:36)
flutter: #1 _ShapedWidgetState.filterPoll (package:moi_polls_app/pages/home.page.dart:1484:15)
flutter: #2 _ShapedWidgetState.build.<anonymous closure>.<anonymous closure>.<anonymous closure> (package:moi_polls_app/pages/home.page.dart:1896:45)
flutter: #3 _InkResponseState._handleTap (package:flutter/src/material/ink_well.dart:507:14)
flutter: #4 _InkResponseState.build.<anonymous closure> (package:flutter/src/material/ink_well.dart:562:30)
flutter: #5 GestureRecognizer.invokeCallback (package:flutter/src/gestures/recognizer.dart:102:24)
flutter: #6 TapGestureRecognizer._checkUp (package:flutter/src/gestures/tap.dart:242:9)
flutter: #7 TapGestureRecognizer.handlePrimaryPointer (package:flutter/src/gestures/tap.dart:175:7)
flutter: #8 PrimaryPointerGestureRecognizer.handleEvent (package:flutter/src/gestures/recognizer.dart:315:9)
flutter: #9 PointerRouter._dispatch (package:flutter/src/gestures/pointer_router.dart:73:12)
flutter: #10 PointerRouter.route (package:flutter/src/gestures/pointer_router.dart:101:11)
flutter: #11 _WidgetsFlutterBinding&BindingBase&GestureBinding.handleEvent (package:flutter/src/gestures/binding.dart:180:19)
flutter: #12 _WidgetsFlutterBinding&BindingBase&GestureBinding.dispatchEvent (package:flutter/src/gestures/binding.dart:158:22)
flutter: #13 _WidgetsFlutterBinding&BindingBase&GestureBinding._handlePointerEvent (package:flutter/src/gestures/binding.dart:138:7)
flutter: #14 _WidgetsFlutterBinding&BindingBase&GestureBinding._flushPointerEventQueue (package:flutter/src/gestures/binding.dart:101:7)
flutter: #15 _WidgetsFlutterBinding&BindingBase&GestureBinding._handlePointerDataPacket (package:flutter/src/gestures/binding.dart:85:7)
flutter: #16 _invoke1 (dart:ui/hooks.dart:168:13)
flutter: #17 _dispatchPointerDataPacket (dart:ui/hooks.dart:122:5)
flutter:
flutter: Handler: onTap
flutter: Recognizer:
flutter: TapGestureRecognizer#e99b3(debugOwner: GestureDetector, state: possible, won arena, finalPosition:
flutter: Offset(283.3, 608.7), sent tap down)
如何解决此问题?
推荐答案
如果要复制列表,请使用以下命令:
If you want to copy your list use this:
globals.filteredPollsList = List.from(pollsList);
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