```dart import 'package:flutter/material.dart'; /// Flutter code sample for [SegmentedButton]. void main() { runApp(const SegmentedButtonApp()); } class SegmentedButtonApp extends StatelessWidget { const SegmentedButtonApp({super.key}); @override Widget build(BuildContext context) { return MaterialApp( theme: ThemeData(useMaterial3: true), home: const Scaffold( body: Center( child: Column( mainAxisAlignment: MainAxisAlignment.center, children: [ Spacer(), Text('Single choice'), SingleChoice(), SizedBox(height: 20), Text('Multiple choice'), MultipleChoice(), Spacer(), ], ), ), ), ); } } enum Calendar { day, week, month, year } class SingleChoice extends StatefulWidget { const SingleChoice({super.key}); @override State createState() => _SingleChoiceState(); } class _SingleChoiceState extends State { Calendar calendarView = Calendar.day; @override Widget build(BuildContext context) { return SegmentedButton( segments: const >[ ButtonSegment( value: Calendar.day, label: Text('Day'), icon: Icon(Icons.calendar_view_day)), ButtonSegment( value: Calendar.week, label: Text('Week'), icon: Icon(Icons.calendar_view_week)), ButtonSegment( value: Calendar.month, label: Text('Month'), icon: Icon(Icons.calendar_view_month)), ButtonSegment( value: Calendar.year, label: Text('Year'), icon: Icon(Icons.calendar_today)), ], selected: {calendarView}, onSelectionChanged: (Set newSelection) { setState(() { // By default there is only a single segment that can be // selected at one time, so its value is always the first // item in the selected set. calendarView = newSelection.first; }); }, ); } } enum Sizes { extraSmall, small, medium, large, extraLarge } class MultipleChoice extends StatefulWidget { const MultipleChoice({super.key}); @override State createState() => _MultipleChoiceState(); } class _MultipleChoiceState extends State { Set selection = {Sizes.large, Sizes.extraLarge}; @override Widget build(BuildContext context) { return SegmentedButton( segments: const >[ ButtonSegment(value: Sizes.extraSmall, label: Text('XS')), ButtonSegment(value: Sizes.small, label: Text('S')), ButtonSegment(value: Sizes.medium, label: Text('M')), ButtonSegment( value: Sizes.large, label: Text('L'), ), ButtonSegment(value: Sizes.extraLarge, label: Text('XL')), ], selected: selection, onSelectionChanged: (Set newSelection) { setState(() { selection = newSelection; }); }, multiSelectionEnabled: true, ); } } ```