| // 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. |
| |
| import 'package:flutter/material.dart'; |
| |
| /// Flutter code sample for M3 [Checkbox] with error state. |
| |
| void main() => runApp(const CheckboxExampleApp()); |
| |
| class CheckboxExampleApp extends StatelessWidget { |
| const CheckboxExampleApp({super.key}); |
| |
| @override |
| Widget build(BuildContext context) { |
| return MaterialApp( |
| theme: ThemeData(useMaterial3: true, colorSchemeSeed: const Color(0xff6750a4)), |
| title: 'Checkbox Sample', |
| home: Scaffold( |
| appBar: AppBar(title: const Text('Checkbox Sample')), |
| body: const Center( |
| child: CheckboxExample(), |
| ), |
| ), |
| ); |
| } |
| } |
| |
| class CheckboxExample extends StatefulWidget { |
| const CheckboxExample({super.key}); |
| |
| @override |
| State<CheckboxExample> createState() => _CheckboxExampleState(); |
| } |
| |
| class _CheckboxExampleState extends State<CheckboxExample> { |
| bool? isChecked = true; |
| |
| @override |
| Widget build(BuildContext context) { |
| return Column( |
| mainAxisAlignment: MainAxisAlignment.center, |
| children: <Widget>[ |
| Checkbox( |
| tristate: true, |
| value: isChecked, |
| onChanged: (bool? value) { |
| setState(() { |
| isChecked = value; |
| }); |
| }, |
| ), |
| Checkbox( |
| isError: true, |
| tristate: true, |
| value: isChecked, |
| onChanged: (bool? value) { |
| setState(() { |
| isChecked = value; |
| }); |
| }, |
| ), |
| Checkbox( |
| isError: true, |
| tristate: true, |
| value: isChecked, |
| onChanged: null, |
| ), |
| ], |
| ); |
| } |
| } |