我开始在 flutter 中学习 Getx，并使用导航。
我想设置unknownRoute，以防命名路由中存在拼写错误等，因此应用程序应该转到默认页面。
我确实喜欢这样：
return GetMaterialApp(
title: 'Named navigation',
unknownRoute: GetPage(name: '/notfound', page: () => UnknownRoutePage()),
initialRoute: '/', // this defines with route will be opened first
getPages: [
GetPage(name: '/', page: () => MyNavigationNamed()),
GetPage(name: '/second', page: () => SecondScreenNamed()),
GetPage(name: '/third', page: () => ThirdParametersScreenNamed()),
GetPage(
name: '/third_with_built_param/:someValue',
page: () => ThirdParametersScreenNamed()),
],
我有小部件：
class UnknownRoutePage extends StatelessWidget {
@override
Widget build(BuildContext context) {
return Scaffold(
body: Container(child: Text('UNKNOWN ROUTE')));
}
}
但是，当我尝试通过在路线名称中犯错误来测试它时，如下所示：
ElevatedButton(
onPressed: () {
Get.toNamed(
'/s'); //THIS IS A DUMMY INCORRECT NAME TO TESTING
},
child: Text('Error in route name, goes to defalt set above.'),
),
我希望我的 UnknownRoutePage() 打开。
但是我收到这个消息：
The following assertion was thrown building Directionality(textDirection: ltr):
'package:flutter/src/widgets/framework.dart': Failed assertion: line 5033 pos 14: '_dependents.isEmpty': is not true.
Either the assertion indicates an error in the framework itself, or we should provide substantially more information in this error message to help you determine and fix the underlying cause.
In either case, please report this assertion by filing a bug on GitHub:
https://github.com/flutter/flutter/issues/new?template=2_bug.md
The relevant error-causing widget was:
Directionality file:///Users/reuvenberman/Developer/flutter/.pub-cache/hosted/pub.dartlang.org/get-4.3.8/lib/get_navigation/src/root/get_material_app.dart:217:12
When the exception was thrown, this was the stack:
#2 InheritedElement.debugDeactivated.<anonymous closure> (package:flutter/src/widgets/framework.dart:5033:14)
#3 InheritedElement.debugDeactivated (package:flutter/src/widgets/framework.dart:5035:6)
#4 _InactiveElements._deactivateRecursively.<anonymous closure> (package:flutter/src/widgets/framework.dart:1869:15)
#5 _InactiveElements._deactivateRecursively (package:flutter/src/widgets/framework.dart:1871:6)
#6 ComponentElement.visitChildren (package:flutter/src/widgets/framework.dart:4628:14)
...
====================================================================================================
======== Exception caught by widgets library =======================================================
The following assertion was thrown while finalizing the widget tree:
Duplicate GlobalKey detected in widget tree.
The following GlobalKey was specified multiple times in the widget tree. This will lead to parts of the widget tree being truncated unexpectedly, because the second time a key is seen, the previous instance is moved to the new location. The key was:
- [LabeledGlobalKey<NavigatorState>#56deb Key Created by default]
This was determined by noticing that after the widget with the above global key was moved out of its previous parent, that previous parent never updated during this frame, meaning that it either did not update at all or updated before the widget was moved, in either case implying that it still thinks that it should have a child with that global key.
The specific parent that did not update after having one or more children forcibly removed due to GlobalKey reparenting is:
- Directionality(textDirection: ltr)
A GlobalKey can only be specified on one widget at a time in the widget tree.
When the exception was thrown, this was the stack:
#0 BuildOwner.finalizeTree.<anonymous closure> (package:flutter/src/widgets/framework.dart:2900:15)
#1 BuildOwner.finalizeTree (package:flutter/src/widgets/framework.dart:2925:8)
#2 WidgetsBinding.drawFrame (package:flutter/src/widgets/binding.dart:877:19)
#3 RendererBinding._handlePersistentFrameCallback (package:flutter/src/rendering/binding.dart:328:5)
#4 SchedulerBinding._invokeFrameCallback (package:flutter/src/scheduler/binding.dart:1144:15)
...
为什么这不起作用？
Thanks
