在导航中使用带有 GlobalKeys 的小部件

Question

我的“主要”小部件必须具有全局键。如果我使用 apushNamed或等效项导航到它，它会生成关于小部件树中重复键的异常。我只能pop使用这个小部件，但这严重降低了我的导航选项和小部件的可重用性。

我已经包含了一个小型复制案例的来源，运行该应用程序，单击Login主页上的按钮，输入 3 个字符的登录名和 3 个字符的密码，然后Login.

有什么想法吗？在没有 的情况下重新设计GlobalKey是一项重大任务。

flutter: ??? EXCEPTION CAUGHT BY WIDGETS LIBRARY ????????????????????????????????????????????????????????????
flutter: The following assertion was thrown while finalizing the widget tree:
flutter: Duplicate GlobalKey detected in widget tree.
flutter: The following GlobalKey was specified multiple times in the widget tree. This will lead to parts of
flutter: the widget tree being truncated unexpectedly, because the second time a key is seen, the previous
flutter: instance is moved to the new location. The key was:
flutter: - [GlobalKey#1c91e navKey]
flutter: This was determined by noticing that after the widget with the above global key was moved out of its
flutter: previous parent, that previous parent never updated during this frame, meaning that it either did
flutter: not update at all or updated before the widget was moved, in either case implying that it still
flutter: thinks that it should have a child with that global key.
flutter: The specific parent that did not update after having one or more children forcibly removed due to
flutter: GlobalKey reparenting is:
flutter: - Semantics(container: false, properties: SemanticsProperties, label: null, value: null, hint: null,
flutter: hintOverrides: null, renderObject: RenderSemanticsAnnotations#147f5 NEEDS-PAINT)
flutter: A GlobalKey can only be specified on one widget at a time in the widget tree.
flutter:
flutter: When the exception was thrown, this was the stack:
flutter: #0      BuildOwner.finalizeTree.<anonymous closure> 
flutter: #1      BuildOwner.finalizeTree 
flutter: #2      _WidgetsFlutterBinding&BindingBase&GestureBinding&ServicesBinding&SchedulerBinding&PaintingBinding&SemanticsBinding&RendererBinding&WidgetsBinding.drawFrame 
flutter: #3      _WidgetsFlutterBinding&BindingBase&GestureBinding&ServicesBinding&SchedulerBinding&PaintingBinding&SemanticsBinding&RendererBinding._handlePersistentFrameCallback 
flutter: #4      _WidgetsFlutterBinding&BindingBase&GestureBinding&ServicesBinding&SchedulerBinding._invokeFrameCallback 
flutter: #5      _WidgetsFlutterBinding&BindingBase&GestureBinding&ServicesBinding&SchedulerBinding.handleDrawFrame 
flutter: #6      _WidgetsFlutterBinding&BindingBase&GestureBinding&ServicesBinding&SchedulerBinding._handleDrawFrame 
flutter: #10     _invoke  (dart:ui/hooks.dart:236:10)
flutter: #11     _drawFrame  (dart:ui/hooks.dart:194:3)
flutter: (elided 3 frames from package dart:async)
flutter: ????????????????????????????????????????????????????????????????????????????????????????????????????
flutter: Another exception was thrown: Multiple widgets used the same GlobalKey.

flutter: ??? EXCEPTION CAUGHT BY WIDGETS LIBRARY ????????????????????????????????????????????????????????????
flutter: The following assertion was thrown while finalizing the widget tree:
flutter: Duplicate GlobalKey detected in widget tree.
flutter: The following GlobalKey was specified multiple times in the widget tree. This will lead to parts of
flutter: the widget tree being truncated unexpectedly, because the second time a key is seen, the previous
flutter: instance is moved to the new location. The key was:
flutter: - [GlobalKey#1c91e navKey]
flutter: This was determined by noticing that after the widget with the above global key was moved out of its
flutter: previous parent, that previous parent never updated during this frame, meaning that it either did
flutter: not update at all or updated before the widget was moved, in either case implying that it still
flutter: thinks that it should have a child with that global key.
flutter: The specific parent that did not update after having one or more children forcibly removed due to
flutter: GlobalKey reparenting is:
flutter: - Semantics(container: false, properties: SemanticsProperties, label: null, value: null, hint: null,
flutter: hintOverrides: null, renderObject: RenderSemanticsAnnotations#147f5 NEEDS-PAINT)
flutter: A GlobalKey can only be specified on one widget at a time in the widget tree.
flutter:
flutter: When the exception was thrown, this was the stack:
flutter: #0      BuildOwner.finalizeTree.<anonymous closure> 
flutter: #1      BuildOwner.finalizeTree 
flutter: #2      _WidgetsFlutterBinding&BindingBase&GestureBinding&ServicesBinding&SchedulerBinding&PaintingBinding&SemanticsBinding&RendererBinding&WidgetsBinding.drawFrame 
flutter: #3      _WidgetsFlutterBinding&BindingBase&GestureBinding&ServicesBinding&SchedulerBinding&PaintingBinding&SemanticsBinding&RendererBinding._handlePersistentFrameCallback 
flutter: #4      _WidgetsFlutterBinding&BindingBase&GestureBinding&ServicesBinding&SchedulerBinding._invokeFrameCallback 
flutter: #5      _WidgetsFlutterBinding&BindingBase&GestureBinding&ServicesBinding&SchedulerBinding.handleDrawFrame 
flutter: #6      _WidgetsFlutterBinding&BindingBase&GestureBinding&ServicesBinding&SchedulerBinding._handleDrawFrame 
flutter: #10     _invoke  (dart:ui/hooks.dart:236:10)
flutter: #11     _drawFrame  (dart:ui/hooks.dart:194:3)
flutter: (elided 3 frames from package dart:async)
flutter: ????????????????????????????????????????????????????????????????????????????????????????????????????
flutter: Another exception was thrown: Multiple widgets used the same GlobalKey.

Answer 1

当您使用pushNamed新路线时，新路线会添加到现有路线之上。

pushNamed您可以使用，而不是使用pushReplacementNamed，因此现有的小部件将从导航堆栈中删除并替换为新的。