Flutter实现仿微信底部菜单栏功能

 import 'package:flutter/material.dart'; void main() => runApp(MyApp()); class MyApp extends StatelessWidget{ @override Widget build(BuildContext context) { return MaterialApp( home: Scaffold( body: MyHomePage(), ), ); } } class MyHomePage extends StatefulWidget{ MyHomePage({Key key}) : super(key:key); @override _MyHomePageState createState() => _MyHomePageState(); @override Widget build(BuildContext context) { // TODO: implement build return null; } } class _MyHomePageState extends State { int _selectedIndex = 1;//当前选中项的索引 final _widgetOptions = [ Text('Index 0: 微信'), Text('Index 1: 通讯录'), Text('Index 2: 发现'), Text('Index 3：我') ]; @override Widget build(BuildContext context) { return Scaffold( appBar: AppBar( title: Text('仿微信'), ), body: Center( child: _widgetOptions.elementAt(_selectedIndex),//居中显示某个文本 ), //底部导航按钮,包含图标及文本 bottomNavigationBar: BottomNavigationBar( items: [ BottomNavigationBarItem(icon: Icon(Icons.chat),backgroundColor:Colors.green,title: Text('微信')),//设置背景颜色和icon的描述 BottomNavigationBarItem(icon: Icon(Icons.contacts),backgroundColor:Colors.green,title: Text('通讯录')), BottomNavigationBarItem(icon: Icon(Icons.account_circle),backgroundColor:Colors.green,title: Text('发现')), BottomNavigationBarItem(icon: Icon(Icons.memory),backgroundColor:Colors.green,title: Text('我')), ], //    backgroundColor: Colors.green, currentIndex: _selectedIndex,//当前选中项的索引 fixedColor: Colors.deepPurple,//选项中项的颜色 onTap:_onItemTapped,//选择按下处理 ), ); } //选择按下处理 void _onItemTapped(int index) { setState(() { _selectedIndex = index; }); } }