import 'package:flutter/material.dart';

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

class MyApp extends StatelessWidget {
  const MyApp({super.key});

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      debugShowCheckedModeBanner: false,
      theme: ThemeData(useMaterial3: true),
      home: const Example(),
    );
  }
}

class Example extends StatelessWidget {
  const Example({super.key});

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: const Text('Sample'),
      ),
      body: Center(
        child: FilledButton(
          onPressed: () {
            ScaffoldMessenger.of(context).showMaterialBanner(
              MaterialBanner(
                elevation: 4.0,
                dividerColor: Colors.green,
                surfaceTintColor: Colors.red,
                shadowColor: Colors.yellow,
                content: const Text('MaterialBanner via ScaffoldMessenger'),
                padding: const EdgeInsets.all(24),
                actions: <Widget>[
                  TextButton(
                    onPressed: () {
                      ScaffoldMessenger.of(context).clearMaterialBanners();
                    },
                    child: const Text('Button'),
                  ),
                ],
              ),
            );
          },
          child: const Text('Show Banner via ScaffoldMessenger'),
        ),
      ),
    );
  }
}