flutter stateful widgte non final field

Flutter Stateful Widget Non-Final Field

In Flutter, a stateful widget is a widget that can change its internal state during its lifetime. Stateful widgets are used when the UI needs to update dynamically in response to user interactions or other events.

When declaring a stateful widget in Flutter, you can use non-final fields to store mutable data within the widget's state. Non-final fields can be modified and updated throughout the widget's lifecycle.

Here's an example of a Flutter stateful widget with a non-final field:

class MyStatefulWidget extends StatefulWidget {
  @override
  _MyStatefulWidgetState createState() => _MyStatefulWidgetState();
}

class _MyStatefulWidgetState extends State<MyStatefulWidget> {
  int _counter = 0;

  void _incrementCounter() {
    setState(() {
      _counter++;
    });
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text('Stateful Widget Example'),
      ),
      body: Center(
        child: Column(
          mainAxisAlignment: MainAxisAlignment.center,
          children: <Widget>[
            Text(
              'Counter:',
            ),
            Text(
              '$_counter',
              style: Theme.of(context).textTheme.headline4,
            ),
          ],
        ),
      ),
      floatingActionButton: FloatingActionButton(
        onPressed: _incrementCounter,
        tooltip: 'Increment',
        child: Icon(Icons.add),
      ),
    );
  }
}

In this example, the _counter variable is a non-final field that stores the current count. The _incrementCounter method is called when the floating action button is pressed, and it updates the _counter value using the setState function. The UI is then rebuilt to reflect the updated count.

Please note that this is just a basic example, and you can use non-final fields in more complex ways depending on your specific requirements.