CODEWITHSUNDEEP
flutter
Majd Al-Atrash
Majd Al-Atrash

Reputation: 37

The declaration 'setState' isn't referenced

I want when I press the button, the text will immediately turn into OK

A hint appears setState "The declaration 'setState' isn't referenced"

class mainApp extends StatefulWidget {
  @override
  _State createState() => _State();
}

class _State extends State<mainApp> {
    @override
   Widget build(BuildContext context) {
   .   return Scaffold(
   .   .   ...
   .   .   body: pageview(),
   .   );
   }
}

Widget pageview() {
   bool BOOL = false;

   return Row( children: [
      FlatButton(  onPressed: () {    setState(){};   BOOL= true;    } ,child: Text('OK')   ),
      Text( textFun(BOOL), ),
   ]);
}

String(bool BOOL) {
   if(BOOL)
      return 'OK';
   return 'not OK';
}

Upvotes: 1

Views: 1354

Answers (2)

Majd Al-Atrash
Majd Al-Atrash

Reputation: 37

I found the solution as follows: Add a new function to State class, and call it with VoidCallback

bool BOOL = false;

class mainApp extends StatefulWidget {
  @override
  _State createState() => _State();
}

class _State extends State<mainApp> {
    @override
   Widget build(BuildContext context) {
   .   return Scaffold(
   .   .   ...
   .   .   body: pageview(fun),
   .   );
   }

   void fun(){
    setState(() {
      BOOL = true;
    });
  }
}

Widget pageview(VoidCallback fun) {
   return Row( children: [
      FlatButton(  onPressed: fun ,child: Text('OK')   ),
      Text( textFun(BOOL), ),
   ]);
}

String(bool BOOL) {
   if(BOOL)
      return 'OK';
   return 'not OK';
}

Upvotes: 2

Simon Sot
Simon Sot

Reputation: 3136

What you are doing is setting a state without changes and then you change your BOOL variable.

First make changes, then after that you call setState, or change your BOOL inside setState

Upvotes: 0

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