// Copyright 2014 The Flutter Authors. All rights reserved. // Use of this source code is governed by a BSD-style license that can be // found in the LICENSE file. // Flutter code sample for [ScaffoldMessenger.of]. import 'package:flutter/material.dart'; void main() => runApp(const MyApp()); class MyApp extends StatefulWidget { const MyApp({super.key}); @override State<MyApp> createState() => _MyAppState(); } class _MyAppState extends State<MyApp> { final GlobalKey<ScaffoldMessengerState> _scaffoldMessengerKey = GlobalKey<ScaffoldMessengerState>(); int _counter = 0; void _incrementCounter() { setState(() { _counter++; }); if (_counter % 10 == 0) { _scaffoldMessengerKey.currentState!.showSnackBar(const SnackBar( content: Text('A multiple of ten!'), )); } } @override Widget build(BuildContext context) { return MaterialApp( scaffoldMessengerKey: _scaffoldMessengerKey, home: Scaffold( appBar: AppBar(title: const Text('ScaffoldMessenger Demo')), body: Center( child: Column( mainAxisAlignment: MainAxisAlignment.center, children: <Widget>[ 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), ), ), ); } }