Flutter中 BottomNavigationBar 開發(fā)底部導(dǎo)航很方便克滴，
但是初次使用時(shí)會(huì)發(fā)現(xiàn)泊窘，切換頁面后熄驼，狀態(tài)恢復(fù)了，如何保持烘豹。
參考：https://www.cnblogs.com/hupo376787/p/10624636.html
關(guān)鍵點(diǎn)：使用IndexedStack
//body: _children[_currentIndex],
body: IndexedStack(
index: _currentIndex,
children: _children,
)
import 'package:flutter/material.dart';
import './pages/home_page.dart';
import './pages/book_page.dart';
import 'package:bottom_nav_bar_test/pages/movie_page.dart';
import 'package:bottom_nav_bar_test/pages/music_page.dart';
void main() => runApp(MyApp());
class MyApp extends StatelessWidget {
@override
Widget build(BuildContext context) {
return MaterialApp(
title: 'Bottom Navigation',
home: Main(),
theme: ThemeData(primaryColor: Colors.orange),
);
}
}
class Main extends StatefulWidget {
@override
_MainState createState() => _MainState();
}
class _MainState extends State<Main> {
int _currentIndex = 0;
final List<Widget> _children = [Home(), Book(), Music(), Movie()];
final List<BottomNavigationBarItem> _list = <BottomNavigationBarItem>[
BottomNavigationBarItem(
icon: Icon(Icons.home),
title: Text('Home'),
//backgroundColor: Colors.orange
),
BottomNavigationBarItem(
icon: Icon(Icons.book),
title: Text('Book'),
//backgroundColor: Colors.orange
),
BottomNavigationBarItem(
icon: Icon(Icons.music_video),
title: Text('Music'),
//backgroundColor: Colors.orange
),
BottomNavigationBarItem(
icon: Icon(Icons.movie),
title: Text('Movie'),
//backgroundColor: Colors.orange
),
];
@override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
title: Text('Bottom Navigation'),
),
bottomNavigationBar: BottomNavigationBar(
type: BottomNavigationBarType.fixed,
onTap: onTabTapped,
currentIndex: _currentIndex,
items: _list,
),
//body: _children[_currentIndex],
body: IndexedStack(
index: _currentIndex,
children: _children,
),
);
}
void onTabTapped(int index) {
setState(() {
_currentIndex = index;
});
}
}
