| // 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. |
| |
| // Template: dev/snippets/config/templates/stateful_widget_material.tmpl |
| // |
| // Comment lines marked with "▼▼▼" and "▲▲▲" are used for authoring |
| // of samples, and may be ignored if you are just exploring the sample. |
| |
| // Flutter code sample for BottomNavigationBar |
| // |
| //*************************************************************************** |
| //* ▼▼▼▼▼▼▼▼ description ▼▼▼▼▼▼▼▼ (do not modify or remove section marker) |
| |
| // This example shows a [BottomNavigationBar] as it is used within a [Scaffold] |
| // widget. The [BottomNavigationBar] has three [BottomNavigationBarItem] |
| // widgets, which means it defaults to [BottomNavigationBarType.fixed], and |
| // the [currentIndex] is set to index 0. The selected item is |
| // amber. The `_onItemTapped` function changes the selected item's index |
| // and displays a corresponding message in the center of the [Scaffold]. |
| |
| //* ▲▲▲▲▲▲▲▲ description ▲▲▲▲▲▲▲▲ (do not modify or remove section marker) |
| //*************************************************************************** |
| |
| import 'package:flutter/material.dart'; |
| |
| void main() => runApp(const MyApp()); |
| |
| /// This is the main application widget. |
| class MyApp extends StatelessWidget { |
| const MyApp({Key? key}) : super(key: key); |
| |
| static const String _title = 'Flutter Code Sample'; |
| |
| @override |
| Widget build(BuildContext context) { |
| return const MaterialApp( |
| title: _title, |
| home: MyStatefulWidget(), |
| ); |
| } |
| } |
| |
| /// This is the stateful widget that the main application instantiates. |
| class MyStatefulWidget extends StatefulWidget { |
| const MyStatefulWidget({Key? key}) : super(key: key); |
| |
| @override |
| State<MyStatefulWidget> createState() => _MyStatefulWidgetState(); |
| } |
| |
| /// This is the private State class that goes with MyStatefulWidget. |
| class _MyStatefulWidgetState extends State<MyStatefulWidget> { |
| //******************************************************************** |
| //* ▼▼▼▼▼▼▼▼ code ▼▼▼▼▼▼▼▼ (do not modify or remove section marker) |
| |
| int _selectedIndex = 0; |
| static const TextStyle optionStyle = |
| TextStyle(fontSize: 30, fontWeight: FontWeight.bold); |
| static const List<Widget> _widgetOptions = <Widget>[ |
| Text( |
| 'Index 0: Home', |
| style: optionStyle, |
| ), |
| Text( |
| 'Index 1: Business', |
| style: optionStyle, |
| ), |
| Text( |
| 'Index 2: School', |
| style: optionStyle, |
| ), |
| ]; |
| |
| void _onItemTapped(int index) { |
| setState(() { |
| _selectedIndex = index; |
| }); |
| } |
| |
| @override |
| Widget build(BuildContext context) { |
| return Scaffold( |
| appBar: AppBar( |
| title: const Text('BottomNavigationBar Sample'), |
| ), |
| body: Center( |
| child: _widgetOptions.elementAt(_selectedIndex), |
| ), |
| bottomNavigationBar: BottomNavigationBar( |
| items: const <BottomNavigationBarItem>[ |
| BottomNavigationBarItem( |
| icon: Icon(Icons.home), |
| label: 'Home', |
| ), |
| BottomNavigationBarItem( |
| icon: Icon(Icons.business), |
| label: 'Business', |
| ), |
| BottomNavigationBarItem( |
| icon: Icon(Icons.school), |
| label: 'School', |
| ), |
| ], |
| currentIndex: _selectedIndex, |
| selectedItemColor: Colors.amber[800], |
| onTap: _onItemTapped, |
| ), |
| ); |
| } |
| |
| //* ▲▲▲▲▲▲▲▲ code ▲▲▲▲▲▲▲▲ (do not modify or remove section marker) |
| //******************************************************************** |
| |
| } |