Flutter 自定义今日头条版本的组件，及底部按钮切换静态样式

自用 无商业用途！！！！

1. 左右滑动实现标题切换，点击标题也可实现切换；

注意：点击顶部按钮时候会触犯_tabController.index会触发两次，普通左右滑动触发一次，所以为了避免触发两次，需要加如下判断

if (_tabController.animation!.value == _tabController.index) {print('${_tabController.animation!.value} --- ${_tabController.index}');
}

2. 自定义KeepAliveWrapper 缓存页面；

2.1 定义keepAliveWrapper.dart 文件；

import 'package:flutter/material.dart';class KeepAliveWrapper extends StatefulWidget {const KeepAliveWrapper({Key? key, @required this.child, this.keepAlive = true}): super(key: key);final Widget? child;final bool keepAlive;@overrideState<KeepAliveWrapper> createState() => _KeepAliveWrapperState();
}class _KeepAliveWrapperState extends State<KeepAliveWrapper>with AutomaticKeepAliveClientMixin {@overrideWidget build(BuildContext context) {return widget.child!;}@overridebool get wantKeepAlive => widget.keepAlive;@overridevoid didUpdateWidget(covariant KeepAliveWrapper oldWidget) {if (oldWidget.keepAlive != widget.keepAlive) {// keepAlive 状态需要更新，实现在 AutomaticKeepAliveClientMixin 中updateKeepAlive();super.didUpdateWidget(oldWidget);}}
}

2.2 使用

// 引入你自己的路径 记得替换

import '../../util/keepAliveWrapper.dart'; // 引入你自己的路径  记得替换

// 要缓存数据的组件包起来

KeepAliveWrapper(child: Center(child: Text('标题$item内容。。。'),),
)

3. 底部导航切换；

4. 自定义中间大导航；

5.AppBar自定义顶部按钮图标、颜色

6. Tabbar TabBarView实现类似头条顶部导航

6. 1.混入SingleTickerProviderStateMixin

class _HomePageState extends State<HomePage> with SingleTickerProviderStateMixin{}

6.2.定义TabController

late TabController _tabController;
@overridevoid initState() {super.initState();_tabController = TabController(length: _lists.length, vsync: this); // 初始化长度_tabController.addListener(() {if (_tabController.animation!.value == _tabController.index) {print('${_tabController.animation!.value} --- ${_tabController.index}');}});}

6.3、配置TabBar和TabBarView 都需要配置 controller（自查别漏了）

7.Scaffold 中可以使用Scaffold 如何重新自定义第二个Scaffold

7.1 PreferredSize可以改变appBar的高度,再给TabBar 包一个 sizebox 即可！

git地址