// 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 four [BottomNavigationBarItem] // widgets, which means it defaults to [BottomNavigationBarType.shifting], and // the [currentIndex] is set to index 0. The selected item is amber in color. // With each [BottomNavigationBarItem] widget, backgroundColor property is // also defined, which changes the background color of [BottomNavigationBar], // when that item is selected. 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, ), Text( 'Index 3: Settings', 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', backgroundColor: Colors.red, ), BottomNavigationBarItem( icon: Icon(Icons.business), label: 'Business', backgroundColor: Colors.green, ), BottomNavigationBarItem( icon: Icon(Icons.school), label: 'School', backgroundColor: Colors.purple, ), BottomNavigationBarItem( icon: Icon(Icons.settings), label: 'Settings', backgroundColor: Colors.pink, ), ], currentIndex: _selectedIndex, selectedItemColor: Colors.amber[800], onTap: _onItemTapped, ), ); } //* ▲▲▲▲▲▲▲▲ code ▲▲▲▲▲▲▲▲ (do not modify or remove section marker) //******************************************************************** }