flutter_tracker/lib/index_page.dart

import 'package:flutter/material.dart';
import 'package:flutter_tracker/pages/home_page.dart';
import 'package:flutter_tracker/pages/mine_page.dart';
import 'package:flutter_tracker/pages/track_page.dart';

class IndexPage extends StatefulWidget {
  const IndexPage({Key key}) : super(key: key);

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

class _IndexPageState extends State<IndexPage> {
  int navIndex = 0;
  List<Widget> pages = [
    HomePage(url: "http://app.21jingji.com/html/2020yiqing/"),
    //https://xw.qq.com/act/qgfeiyan
    // https://www.ipe.org.cn/MapGZBD/XQMap.html
    //http://m.look.360.cn/subject/400?sign=360_6aa05217&stab=0
    const TrackPage(),
     MinePage(),
  ];
  Widget currentPage;

  @override
  void initState() {
    super.initState();
    currentPage = pages[navIndex];
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      backgroundColor: const Color(0xF1F6F9ff),
      body: currentPage,
      bottomNavigationBar: BottomNavigationBar(
        type: BottomNavigationBarType.fixed,
        currentIndex: navIndex,
        items: const [
          BottomNavigationBarItem(icon: Icon(Icons.home), label: "首页"),
          BottomNavigationBarItem(icon: Icon(Icons.art_track), label: "追踪"),
          BottomNavigationBarItem(icon: Icon(Icons.person), label: "我的"),
        ],
        onTap: (index) {
          setState(() {
            navIndex = index;
            currentPage = pages[navIndex];
          });
        },
      ),
    );
  }
}