当前位置：首页 > article >正文

Flutter仿京东商城APP底部导航实现

article 2024/10/24 15:44:38

01 基础代码

main.dart

import 'package:flutter/material.dart';

void main() {
  runApp(const MyApp());
}

class MyApp extends StatelessWidget {
  const MyApp({super.key});

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'jdshop',
      theme: ThemeData(
        colorScheme: ColorScheme.fromSeed(seedColor: Colors.deepPurple),
        useMaterial3: true,
      ),
      home: const MyHomePage(title: '京东商城'),
    );
  }
}

class MyHomePage extends StatefulWidget {
  const MyHomePage({super.key, required this.title});

  final String title;

  @override
  State<MyHomePage> createState() => _MyHomePageState();
}

class _MyHomePageState extends State<MyHomePage> {
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        backgroundColor: Theme.of(context).colorScheme.inversePrimary,
        title: Text(widget.title),
      ),
      body: const Text("我是首页"),
    );
  }
}

02 配置底部导航

核心代码

bottomNavigationBar: BottomNavigationBar(items: const [
  BottomNavigationBarItem(icon: Icon(Icons.home), label: "首页"),
  BottomNavigationBarItem(icon: Icon(Icons.category), label: "分类"),
])

完整代码

main.dart

import 'package:flutter/material.dart';

void main() {
  runApp(const MyApp());
}

class MyApp extends StatelessWidget {
  const MyApp({super.key});

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'jdshop',
      theme: ThemeData(
        colorScheme: ColorScheme.fromSeed(seedColor: Colors.deepPurple),
        useMaterial3: true,
      ),
      home: const MyHomePage(title: '京东商城'),
    );
  }
}

class MyHomePage extends StatefulWidget {
  const MyHomePage({super.key, required this.title});

  final String title;

  @override
  State<MyHomePage> createState() => _MyHomePageState();
}

class _MyHomePageState extends State<MyHomePage> {
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        backgroundColor: Theme.of(context).colorScheme.inversePrimary,
        title: Text(widget.title),
      ),
      body: const Text("我是首页"),
      bottomNavigationBar: BottomNavigationBar(items: const [
        BottomNavigationBarItem(icon: Icon(Icons.home), label: "首页"),
        BottomNavigationBarItem(icon: Icon(Icons.category), label: "分类"),
      ]),
    );
  }
}

03 抽离底部导航代码

main.dart

import 'package:flutter/material.dart';
import 'pages/tabs/tabs.dart';

void main() {
  runApp(const MyApp());
}

class MyApp extends StatelessWidget {
  const MyApp({super.key});

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'jdshop',
      theme: ThemeData(
        colorScheme: ColorScheme.fromSeed(seedColor: Colors.deepPurple),
        useMaterial3: true,
      ),
      home: const Tabs(title: "京东商城"),
    );
  }
}

pages/tabs/tabs.dart

import 'package:flutter/material.dart';

class Tabs extends StatefulWidget {
  const Tabs({super.key, required this.title});

  final String title; // 标题

  @override
  TabsState createState() => TabsState();
}

class TabsState extends State<Tabs> {
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        backgroundColor: Theme.of(context).colorScheme.inversePrimary,
        title: Text(widget.title),
      ),
      body: const Text("我是首页"),
      bottomNavigationBar: BottomNavigationBar(items: const [
        BottomNavigationBarItem(icon: Icon(Icons.home), label: "首页"),
        BottomNavigationBarItem(icon: Icon(Icons.category), label: "分类"),
      ]),
    );
  }
}

04 增加底部导航选项

核心代码

1.添加索引

int _currentIndex = 0;

2.配置底部导航

bottomNavigationBar: BottomNavigationBar(
  currentIndex: _currentIndex,
  onTap: (index) {
    setState(() {
      _currentIndex = index;
    });
  },
  type: BottomNavigationBarType.fixed, // 超过2个必须配置这个才显示
  items: const [
    BottomNavigationBarItem(icon: Icon(Icons.home), label: "首页"),
    BottomNavigationBarItem(icon: Icon(Icons.category), label: "分类"),
    BottomNavigationBarItem(icon: Icon(Icons.shopping_cart), label: "购物车"),
    BottomNavigationBarItem(icon: Icon(Icons.people), label: "我的"),
  ]),
);

完整代码

pages/tabs/tabs.dart

import 'package:flutter/material.dart';

class Tabs extends StatefulWidget {
  const Tabs({super.key, required this.title});

  final String title; // 标题

  @override
  _TabsState createState() => _TabsState();
}

class _TabsState extends State<Tabs> {
  int _currentIndex = 0;

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        backgroundColor: Theme.of(context).colorScheme.inversePrimary,
        title: Text(widget.title),
      ),
      body: const Text("我是首页"),
      bottomNavigationBar: BottomNavigationBar(
          currentIndex: _currentIndex,
          onTap: (index) {
            setState(() {
              _currentIndex = index;
            });
          },
          type: BottomNavigationBarType.fixed, // 超过2个必须配置这个才显示
          items: const [
            BottomNavigationBarItem(icon: Icon(Icons.home), label: "首页"),
            BottomNavigationBarItem(icon: Icon(Icons.category), label: "分类"),
            BottomNavigationBarItem(icon: Icon(Icons.shopping_cart), label: "购物车"),
            BottomNavigationBarItem(icon: Icon(Icons.people), label: "我的"),
          ]),
    );
  }
}