Lifecycle of a StatefulWidget

main.dart

import 'package:flutter/material.dart';

void main() {
  runApp(const MainApp());
}

class MainApp extends StatefulWidget {
  const MainApp({super.key});

  @override
  State<MainApp> createState() => _MainAppState();
}

class _MainAppState extends State<MainApp> {
  bool isDark = false;
  int counter = 0;
  List<Key> keys = [GlobalKey(), GlobalKey()];
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      theme: isDark ? ThemeData.dark() : ThemeData.light(),
      home: Scaffold(
        appBar: AppBar(
          title: const Text('Flutter Dark Mode'),
          actions: [
            Switch(
              value: isDark,
              onChanged: (value) {
                setState(() {
                  isDark = value;
                });
              },
            ),
          ],
        ),
        body: Column(
          children: [
            StatefulExample(count: counter, key: keys[0]),
            StatefulExample(count: counter, key: keys[1]),
          ],
        ),
        floatingActionButton: Row(
          children: [
            FloatingActionButton(
                onPressed: () {
                  setState(() {
                    keys.insert(0, keys.removeAt(1));
                  });
                },
                child: const Icon(Icons.rotate_left)),
            FloatingActionButton(
              onPressed: () {
                setState(() {
                  counter++;
                });
              },
              child: const Icon(Icons.add),
            ),
          ],
        ),
      ),
    );
  }
}

class StatefulExample extends StatefulWidget {
  const StatefulExample({Key? key, required this.count}) : super(key: key);

  final int count;

  @override
  _StatefulExampleState createState() => _StatefulExampleState();
}

class _StatefulExampleState extends State<StatefulExample> {
  @override
  Widget build(BuildContext context) {
    return Center(
      child: Text('Hello World ${widget.count}!',
          style: Theme.of(context).textTheme.displayLarge),
    );
  }

  @override
  void initState() {
    super.initState();
    print('initState');
  }

  @override
  void didChangeDependencies() {
    super.didChangeDependencies();
    print('didChangeDependencies');
  }

  @override
  void didUpdateWidget(covariant StatefulExample oldWidget) {
    super.didUpdateWidget(oldWidget);
    print('didUpdateWidget');
  }

  @override
  void deactivate() {
    super.deactivate();
    print('deactivate');
  }

  @override
  void dispose() {
    print('dispose');
    super.dispose();
  }
}