上效果：

有些不能理解官方例子里的动画为什么没有效果，有可能是我写法不对
后续如果有动画效果修复了，再更新这篇，没有动画效果，总觉得感受的丝滑效果差了很多

上代码：

import 'package:flutter/material.dart';
import 'package:flutter/foundation.dart';
import 'package:logging/logging.dart';const TAG = 'OfficePageViewDemo';class OfficePageViewDemo extends StatelessWidget {const OfficePageViewDemo({super.key});@overrideWidget build(BuildContext context) {return MaterialApp(home: Scaffold(appBar: AppBar(title: Text('PageView Demo!'),),body: PageViewDemo(),),);}
}class PageViewDemo extends StatefulWidget {const PageViewDemo({super.key});@overridecreateState() => _PageViewDemoState();
}class _PageViewDemoState extends State<PageViewDemo>with TickerProviderStateMixin {late PageController _pageViewController;late TabController _tabController;int _currentPageIndex = 0;@overridevoid initState() {super.initState();_pageViewController = PageController();_tabController = TabController(length: 3, vsync: this);}@overridevoid dispose() {super.dispose();_pageViewController.dispose();_tabController.dispose();}@overrideWidget build(BuildContext context) {final TextTheme textTheme = Theme.of(context).textTheme;return Stack(alignment: Alignment.bottomCenter,children: [PageView(controller: _pageViewController,onPageChanged: _handlePageViewChanged,children: [Center(child: Text('First Page',style: textTheme.titleLarge,),),Center(child: Text('Second Page',style: textTheme.titleLarge,),),Center(child: Text('Third Page',style: textTheme.titleLarge,),),],),PageIndicator(tabController: _tabController,currentPageIndex: _currentPageIndex,onUpdateCurrentPageIndex: _updateCurrentPageIndex,isOnDesktopAndWeb: _isOnDesktopAndWeb,)],);}void _handlePageViewChanged(int currentPageIndex) {Logger(TAG).info('_handlePageViewChanged called! currentPageIndex=$currentPageIndex');if (!_isOnDesktopAndWeb) {return;}_tabController.index = currentPageIndex;setState(() {_currentPageIndex = currentPageIndex;});}void _updateCurrentPageIndex(int index) {Logger(TAG).info('_updateCurrentPageIndex called! index=$index');_tabController.index = index;_pageViewController.animateToPage(index,duration: const Duration(microseconds: 400 * 2), curve: Curves.linear);}bool get _isOnDesktopAndWeb {if (kIsWeb) {return true;}switch (defaultTargetPlatform) {case TargetPlatform.macOS:case TargetPlatform.linux:case TargetPlatform.windows:return true;case TargetPlatform.android:case TargetPlatform.iOS:case TargetPlatform.fuchsia:return false;}}
}class PageIndicator extends StatelessWidget {const PageIndicator({super.key,required this.tabController,required this.currentPageIndex,required this.onUpdateCurrentPageIndex,required this.isOnDesktopAndWeb});final int currentPageIndex;final TabController tabController;final void Function(int) onUpdateCurrentPageIndex;final bool isOnDesktopAndWeb;@overrideWidget build(BuildContext context) {if (!isOnDesktopAndWeb) {return const SizedBox();}final ColorScheme colorScheme = Theme.of(context).colorScheme;return Padding(padding: const EdgeInsets.all(8.0),child: Row(mainAxisAlignment: MainAxisAlignment.center,children: [IconButton(splashRadius: 16.0,padding: EdgeInsets.zero,onPressed: () => {if (currentPageIndex == 0){}else{onUpdateCurrentPageIndex(currentPageIndex - 1)}},icon: const Icon(Icons.arrow_left_rounded,size: 32.0,)),TabPageSelector(controller: tabController,color: colorScheme.surface,selectedColor: colorScheme.primary,),IconButton(splashRadius: 16.0,padding: EdgeInsets.zero,onPressed: () => {if (currentPageIndex == 2){}else{onUpdateCurrentPageIndex(currentPageIndex + 1)}},icon: const Icon(Icons.arrow_right_rounded,size: 32.0,)),],),);}
}

事实就是官方代码，不过有点细微差别
有解决动画效果的回复一下蛤！

还差一个拖动边界框改变 widget 的宽高效果；

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