Flutterラボ リリース3周年記念! プロコースが1ヶ月の料金で2ヶ月間受けられる、実質半額セール (2024年3月17日まで・先着)

アイコンと併せて使うボタンです。
import 'package:flutter/material.dart';

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

class MyApp extends StatelessWidget {
  const MyApp({Key? key}) : super(key: key);

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Flutter Demo',
      theme: ThemeData(
        primarySwatch: Colors.blue,
      ),
      home: const MyHomePage(title: 'Flutter Demo Home Page'),
    );
  }
}

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

  final String title;

  @override
  State<MyHomePage> createState() => _MyHomePageState();
}

class _MyHomePageState extends State<MyHomePage> {
    double _volume = 0.0;

  @override
  Widget build(BuildContext context) {
    return Column(
      mainAxisSize: MainAxisSize.min,
      children: <Widget>[
        IconButton(
          icon: const Icon(Icons.volume_up),
          tooltip: 'Increase volume by 10',
          onPressed: () {
            setState(() {
              _volume += 10;
            });
          },
        ),
        Text('Volume : $_volume')
      ],
    );
  }
}