在小部件树中检测到重复 GlobalKey

Thanks to Gunter's commments, I determined that this is because the Screens are not being properly disposed.

Flutter's pushReplacement makes a call to Route.dispose which will ultimately dispose the screen.

I am still unsure as to this comes into play:

widget must be inserted into the new location in the same animation frame

I'm not sure what situation would benefit from such trickery. However, my problem is solved. I just need to make a call to pop or replace.

Here are the available options:

• Use push from A to B and just Navigator.pop from B
• Use pushReplacement from A to B and from B to A

I've recently started playing with Fluro for routing and there are a few more ways to to handle these situations (Note the optional argument replace):

• Use router.navigateTo(context, route, replace: false) from A to B and Navigator.pop from B
• Use router.navigateTo(context, route, replace: true) from A to B the same from B to A (the key is replace: true)

I also had a similar error. My answer was that after I updated Flutter some widgets no longer had child or children properties. In my case it was the CircleAvatar. The build doesn't error out initially, but when navigating back and forth through the app it will fail.

*Please review all widgets that require a child then review the updated documentation and make sure you're parameters are still correct.

In my case I wanted to use the static GlobalKey<ScaffoldState> _scaffoldKey but when I used the same widget multiple times it gave this duplicate error.

I wanted to give it a unique string and still use this scaffold state. So I ended up using:

static GlobalObjectKey<ScaffoldState> _scaffoldKey

and in the initState:

_scaffoldKey = new GlobalObjectKey<ScaffoldState>(id);

Edit: Actually, silly me. I just simply removed the static and made it GlobalKey again :)

In my case, it likes a hot reload bug. Just restart debugging works for me.

Best way to solve that, which worked for me:

class _HomeScreenState extends State<HomeScreen> {
GlobalKey<FormState> _homeKey = GlobalKey<FormState>(debugLabel: '_homeScreenkey');
@override
Widget build(BuildContext context) {
return Container(
key: _homeKey,
);
}
}

please take SingleChildScrollview:

and after if you use the bloc pettern then use strem with broadcast

code is here:

        body: Container(
decoration: BoxDecoration(
image: DecorationImage(
image: AssetImage('assets/images/abcd.jpg'),
fit: BoxFit.cover,
),
),
child: Container(child:Form(key: _key,
child: Padding(
padding: EdgeInsets.symmetric(vertical: 100.0, horizontal: 20.0),
child: SingleChildScrollView(child:Column(
children: <Widget>[
Padding(
padding: const EdgeInsets.all(10.0),
child: Image.asset('assets/images/logo.png', height: 80, width:80,),
),
email(),
Padding(
padding: EdgeInsets.all(5.0),
),
password(),
row(context),
],
),
),
),
),
),
),
resizeToAvoidBottomPadding: false,
);
}

and the bloc pettern code is here:

    final _email = StreamController<String>.broadcast();
final _password = StreamController<String>.broadcast();


Stream<String> get email => _email.stream.transform(validateEmail);
Stream<String> get password=> _password.stream.transform(validatepassword);


Function(String) get changeEmail=> _email.sink.add;
Function(String) get changePassword => _password.sink.add;


dispose(){


_email.close();
_password.close();
}


}


final bloc=Bloc();

Remove the static and final type from the key variable so if

static final GlobalKey<FormState> _abcKey = GlobalKey<FormState>();

change it to

GlobalKey<FormState> _abcKey = GlobalKey<FormState>();

I am not sure why no one has mentioned this yet but, in my case, I simply changed a widget from Stateful to Stateless. To fix the error, you have to restart the application instead of doing a hot reload.

I had a similar problem. in my case the problem was that I had a function in dispose method of screen B and it wouldn't execute properly. I just removed it and the problem was fixed.

so be sure your dispose method is executed properly in all screens.

I had this issue too. I had a four screen bottom tabbed application and a 'logout' method. However, that logout method was calling a pushReplacementNamed. This prevented the class that held the global keys (different from the logout function) from calling dispose.

The resolution was to change pushReplacementNamed with popAndPushNamed to get back to my 'login' screen.

Make sure that you don't have a Form parent and a Form child with the same key

This happened to me, what I did was enclosed the whole view into a navigator using an extension I made

Widget addNavigator() => Navigator(
onGenerateRoute: (_) => MaterialPageRoute(
builder: (context2) => Builder(
builder: (context) => this,
),
),
);

I also got this error. There was a static bloc object in a class and I removed the static keyword which fixed the error.

Events should be added by using the BlocProvider anyway.

I had similar issue on a StatelessWidget class, Converted it to StatefulWidget and error is gone.

If you have multiple forms with different widgets, you must use separate GlobalKey for each form. Like I have two forms, one with Company signup & one with Profile. So, I declared

GlobalKey<FormState> signUpCompanyKey = GlobalKey<FormState>();
GlobalKey<FormState> signUpProfileKey = GlobalKey<FormState>();