main.dart file for theme example

main.dart

import 'package:flutter/material.dart';
import 'package:theme_example/home.dart';

void main() => runApp(MyApp());

class MyApp extends StatefulWidget {
  @override
  _MyAppState createState() => _MyAppState();

  static _MyAppState? of(BuildContext context) => context.findAncestorStateOfType<_MyAppState>();
}

class _MyAppState extends State<MyApp> {
  ThemeMode _themeMode = ThemeMode.light;
  void changeTheme(ThemeMode themeMode) {
    setState(() {
      _themeMode = themeMode;
    });
  }

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Material App',
      themeMode: _themeMode,
      theme: ThemeData(),
      darkTheme: ThemeData.dark(),
      home: Home(),
    );
  }
}