import "package:flutter/material.dart"; void main() { runApp(const MyApp()); } class MyApp extends StatelessWidget { const MyApp({super.key}); @override Widget build(BuildContext context) => MaterialApp( title: "Flutter Demo", theme: ThemeData( colorScheme: ColorScheme.fromSeed(seedColor: Colors.deepPurple), useMaterial3: true, ), home: const MyHomePage(title: "Flutter Demo Home Page"), ); } class MyHomePage extends StatefulWidget { const MyHomePage({required this.title, super.key}); final String title; @override State createState() => _MyHomePageState(); } class _MyHomePageState extends State { int _counter = 0; void _incrementCounter() { setState(() { _counter++; }); } @override Widget build(BuildContext context) => Scaffold( appBar: AppBar( backgroundColor: Theme.of(context).colorScheme.inversePrimary, title: Text(widget.title), ), body: Center( child: Column( mainAxisAlignment: MainAxisAlignment.center, children: [ const Text( "You have pushed the button this many times:", ), Text( "$_counter", style: Theme.of(context).textTheme.headlineMedium, ), ], ), ), floatingActionButton: FloatingActionButton( onPressed: _incrementCounter, tooltip: "Increment", child: const Icon(Icons.add), ), // This trailing comma makes auto-formatting nicer for build methods. ); }