BottomNavigationBar结合TabBar实现类似头条框架

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效果图

prev.gif

1.实现底部BottomNavigationBar

Tabs.dart

import 'package:flutter/material.dart';
import 'package:newsscaffold/pages/tabs/Ixigua.dart';
import 'package:newsscaffold/pages/tabs/User.dart';
import 'package:newsscaffold/pages/tabs/VideoHall.dart';

import 'tabs/Home.dart';

class Tabs extends StatefulWidget {
final index;
Tabs({Key key,this.index=0}):super(key:key);
@override
_TabsState createState() => _TabsState(this.index);
}

class _TabsState extends State<Tabs> {
_TabsState(index){
  this._currentIndex=index;
}
int _currentIndex ;
List _pageList = [HomePage(), IxiguaPage(), VideoHallPage(),UserPage()];

@override
Widget build(BuildContext context) {
  return Scaffold(
//      appBar: AppBar(
//        // Here we take the value from the MyHomePage object that was created by
//        // the App.build method, and use it to set our appbar title.
//        title: Text("今日头条"),
//      ),
    body: this._pageList[this._currentIndex],
    bottomNavigationBar: BottomNavigationBar(
        currentIndex: this._currentIndex,
        //图标大小
        iconSize: 35,
        //选中颜色
        fixedColor: Colors.redAccent,
        //底部可以设置多个按钮
        type: BottomNavigationBarType.fixed,
        onTap: (index) {
          setState(() {
            this._currentIndex = index;
          });
        },
        items: [
          BottomNavigationBarItem(icon: Icon(Icons.home), title: Text("首页")),
          BottomNavigationBarItem(icon: Icon(Icons.play_arrow), title: Text("西瓜视频")),
          BottomNavigationBarItem(icon: Icon(Icons.slideshow), title: Text("放映厅")),
          BottomNavigationBarItem(icon: Icon(Icons.account_circle), title: Text("我的")),
        ]), // This trailing comma makes auto-formatting nicer for build methods.
  );
}
}

Tabs.dart中的四个页面

2.Home.dart 将TabBar放在AppBar的title中

import 'package:flutter/material.dart';

class HomePage extends StatefulWidget {
@override
_HomePageState createState() => _HomePageState();
}

class _HomePageState extends State<HomePage> with SingleTickerProviderStateMixin{
List<Widget> _tabs = [
  Tab(
    text: "关注",
  ),
  Tab(
    text: "推荐",
  ),
  Tab(
    text: "热榜",
  ),
  Tab(
    text: "科技",
  ),
  Tab(
    text: "免费小说",
  ),
  Tab(
    text: "新时代",
  ),
  Tab(
    text: "抗疫",
  ),
  Tab(
    text: "问答",
  ),
  Tab(
    text: "数码",
  ),
  Tab(
    text: "要闻",
  ),
  Tab(
    text: "视频",
  ),
];
List<Widget> _tabBars = [Center(
  child: Text('关注'),
),
  Center(
    child: Text('推荐'),
  ),
  Center(
    child: Text('热榜'),
  ),
  Center(
    child: Text('科技'),
  ),
  Center(
    child: Text('免费小说'),
  ),
  Center(
    child: Text('新时代'),
  ),
  Center(
    child: Text('抗疫'),
  ),
  Center(
    child: Text('问答'),
  ),
  Center(
    child: Text('数码'),
  ),
  Center(
    child: Text('要闻'),
  ),
  Center(
    child: Text('视频'),
  ),];

TabController _tabController;//注意 在TabBar和TabBarView中都需要配置controller

@override
void initState() {
  super.initState();
  _tabController = new TabController(vsync: this, length: this._tabs.length);
  _tabController.index=1;
  setState(() {

  });
  //监听器
  _tabController.addListener(() {
    //点击切换tab的时候执行了一个动画效果，滑动切换的时候是没有的，在这个过程中触发了一次Listener,所以触发了两次addListener方法
    // 解决点击tab执行2次的问题
    if(_tabController.index ==_tabController.animation.value) {
      //实现自定义的功能
      print(_tabController.index);
    }
  });
}

@override
Widget build(BuildContext context) {
  return Scaffold(
    appBar: AppBar(
      backgroundColor: Colors.white,
      title: TabBar(
        controller: this._tabController,
        indicatorColor: Colors.redAccent,
        labelColor: Colors.redAccent,
        unselectedLabelColor: Colors.black,
        isScrollable: true,
        //和文字等宽
        indicatorSize: TabBarIndicatorSize.label,
        tabs: this._tabs,
      ),
    ),
    body: TabBarView(children: this._tabBars,controller: this._tabController,),
  );
}
}

Ixigua.dart

import 'package:flutter/material.dart';

class IxiguaPage extends StatelessWidget {
@override
Widget build(BuildContext context) {
  return Center(
    child: Text('西瓜视频'),
  );
}
}

VideoHall.dart

import 'package:flutter/material.dart';

class VideoHallPage extends StatelessWidget {
@override
Widget build(BuildContext context) {
  return Center(
    child: Text('放映厅'),
  );
}
}

User.dart

import 'package:flutter/material.dart';

class UserPage extends StatelessWidget {
@override
Widget build(BuildContext context) {
  return Center(
    child: Text('我的'),
  );
}
}

程序入口

main.dart

import 'package:flutter/material.dart';

import 'pages/Tabs.dart';

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

class MyApp extends StatelessWidget {
  // This widget is the root of your application.
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Flutter Demo',
      theme: ThemeData(
        // This is the theme of your application.
        //
        // Try running your application with "flutter run". You'll see the
        // application has a blue toolbar. Then, without quitting the app, try
        // changing the primarySwatch below to Colors.green and then invoke
        // "hot reload" (press "r" in the console where you ran "flutter run",
        // or simply save your changes to "hot reload" in a Flutter IDE).
        // Notice that the counter didn't reset back to zero; the application
        // is not restarted.
        primarySwatch: Colors.blue,
        // This makes the visual density adapt to the platform that you run
        // the app on. For desktop platforms, the controls will be smaller and
        // closer together (more dense) than on mobile platforms.
        visualDensity: VisualDensity.adaptivePlatformDensity,
      ),
      debugShowCheckedModeBanner: false,
      home: Tabs(index: 0,),
    );
  }
}

源码传送门