Android-Flutter-BottomNavigationBar：该如何优雅实现底部导航栏？(1)

最新推荐文章于 2024-08-31 19:16:19 发布

2301_82242844

最新推荐文章于 2024-08-31 19:16:19 发布

阅读量988

点赞数 19

分类专栏：程序员文章标签： android flutter javascript

本文链接：https://blog.youkuaiyun.com/2301_82242844/article/details/137094181

版权

程序员专栏收录该内容

554 篇文章

订阅专栏

// 页面1
import ‘package:flutter/material.dart’;

class PageA extends StatelessWidget {
@override
Widget build(BuildContext context) {
return Center(
child: Text(“PageA”),
);
}
}

// 页面2
import ‘package:flutter/material.dart’;

class PageB extends StatelessWidget {
@override
Widget build(BuildContext context) {
return Center(
child: Text(“PageB”),
);
}
}

// 页面3
import ‘package:flutter/material.dart’;

class PageC extends StatelessWidget {
@override
Widget build(BuildContext context) {
return Center(
child: Text(“PageC”),
);
}
}

// 页面4
import ‘package:flutter/material.dart’;

class PageD extends StatelessWidget {
@override
Widget build(BuildContext context) {
return Center(
child: Text(“PageD”),
);
}
}

4.2 核心代码

main.dart

/**

导入库
**/
import ‘package:flutter/material.dart’;

import ‘PageA.dart’;
import ‘PageB.dart’;
import ‘PageC.dart’;
import ‘PageD.dart’; // Material UI组件库

void main() => runApp(MyApp());

// 无状态控件显示
class MyApp extends StatelessWidget {
@override
Widget build(BuildContext context) {
// 主界面入口返回的组件 = MaterialApp
return MaterialApp(
title: ‘Widget_Demo’, //标题
theme: ThemeData(primarySwatch: Colors.blue), //主题色
home: MyWidget(), // 返回一个Widget对象，用来定义当前应用打开的时候，所显示的界面
);
}
}

class MyWidget extends StatefulWidget {
@override
State createState() {
return new _MyWidgetState();
}
}

class _MyWidgetState extends State {

// 导航栏的item
final List bottomNavItems = [
BottomNavigationBarItem(
backgroundColor: Colors.blue,
icon: Icon(Icons.home),
title: Text(“首页”),
),
BottomNavigationBarItem(
backgroundColor: Colors.green,
icon: Icon(Icons.message),
title: Text(“消息”),
),
BottomNavigationBarItem(
backgroundColor: Colors.amber,
icon: Icon(Icons.shopping_cart),
title: Text(“购物车”),
),
BottomNavigationBarItem(
backgroundColor: Colors.red,
icon: Icon(Icons.person),
title: Text(“个人中心”),
),
];

int currentIndex; // 当前下标

final pages = [PageA(), PageB(), PageC(), PageD()];// 下标对应显示的界面

@override
void initState() {
super.initState();
currentIndex = 0;
}

@override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
title: Text(“底部导航栏”),
),
bottomNavigationBar: BottomNavigationBar(
items: bottomNavItems, // 导航栏下标item
currentIndex: currentIndex, // 当前下标
type: BottomNavigationBarType.fixed,
fixedColor: Colors.green,
iconSize: 15,
onTap: (index) {
_changePage(index); // 点击回调
},
),
body: pages[currentIndex],
);
}