IconButton

sample.packages.flutter.lib.src.material.icon_button.44.

This sample shows an IconButton that uses the Material icon "volume_up" to increase the volume.

  
import 'package:flutter/material.dart';

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

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

  static const String _title = 'Flutter Code Sample';

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: _title,
      home: Scaffold(
        appBar: AppBar(title: const Text(_title)),
        body: const Center(
          child: MyStatefulWidget(),
        ),
      ),
    );
  }
}

double _volume = 0.0;

class MyStatefulWidget extends StatefulWidget {
  const MyStatefulWidget({Key? key}) : super(key: key);

  @override
  State createState() => _MyStatefulWidgetState();
}

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