Flutter: Set global variable using OK button on AlertDialog in StatefulBuilder - flutter

Question

How to set global variable using OK button on AlertDialog in StatefulBuilder?
String stringMain = "My String";
Future<String?> dialogChangeMainContent(BuildContext context) {
return showDialog<String>(
context: context,
builder: (BuildContext context) {
return StatefulBuilder(builder: (context, setState) {
return AlertDialog(
title: const Text('AlertDialog Title'),
content: const Text('AlertDialog description'),
actions: <Widget>[
TextButton(
onPressed: () {
Navigator.pop(context, 'OK');
setState(() {
// setState2();
stringMain = "New String";
});
},
child: const Text('OK'),
),
],
);
});
});
}
I changed StatefulWidget from StatelessWidget, but nothing changes. What I know is the problem is because the button is in the StatefulBuilder. If using BLoC etc, it's too wasteful for only small applications.

Answer 1

I found a way to solve my problem, redrawing (refreshing) the Text (or other widget) in a Stateless Widget from an AlertDialog in a StatefulBuilder. By creating a setState with a different name, for example setStateTarget.
Without having to rebuild the entire page, or without state management like BLoC. My code:
String stringMain = "My String";
#override
Widget build(BuildContext context) {
return Column(
// ....
children: [
StatefulBuilder(builder: (BuildContext context, setStateTarget) {
return Column(children: [
Text(stringMain), // <--- target
TextButton(
onPressed: () => dialogChangeMainContent(context, setStateTarget),
child: const Text('Show Dialog'))
]);
})
],
);
}
Future<String?> dialogChangeMainContent(BuildContext context, StateSetter setStateTarget) {
return showDialog<String>(
context: context,
builder: (BuildContext context) {
return StatefulBuilder(builder: (context, setState) {
return AlertDialog(
title: const Text('AlertDialog Title'),
content: const Text('AlertDialog description'),
actions: <Widget>[
TextButton(
onPressed: () {
Navigator.pop(context, 'OK');
setStateTarget(() {
// setState2();
stringMain = "New String";
});
},
child: const Text('OK'),
),
],
);
});
});
}