如何在tabBarView中使用有状态窗口小部件？

import 'package:flutter/material.dart';

class MyTabbedPage extends StatefulWidget {
  @override
  _MyTabbedPageState createState() => _MyTabbedPageState();
}

class _MyTabbedPageState extends State<MyTabbedPage>
    with SingleTickerProviderStateMixin {
  TabController _tabController;

  @override
  void initState() {
    super.initState();
    _tabController = TabController(length: 3, vsync: this);
  }

  @override
  void dispose() {
    _tabController.dispose();
    super.dispose();
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text('Tabbed Page'),
        bottom: TabBar(
          controller: _tabController,
          tabs: [
            Tab(icon: Icon(Icons.home)),
            Tab(icon: Icon(Icons.business)),
            Tab(icon: Icon(Icons.school)),
          ],
        ),
      ),
      body: TabBarView(
        controller: _tabController,
        children: [
          HomeTab(),
          BusinessTab(),
          SchoolTab(),
        ],
      ),
    );
  }
}

class HomeTab extends StatefulWidget {
  @override
  _HomeTabState createState() => _HomeTabState();
}

class _HomeTabState extends State<HomeTab> {
  int _counter = 0;

  void _incrementCounter() {
    setState(() {
      _counter++;
    });
  }

  @override
  Widget build(BuildContext context) {
    return Center(
      child: Column(
        mainAxisAlignment: MainAxisAlignment.center,
        children: <Widget>[
          Text(
            'Home Tab',
            style: TextStyle(fontSize: 24),
          ),
          Text(
            'Counter: $_counter',
            style: TextStyle(fontSize: 18),
          ),
          RaisedButton(
            child: Text('Increment'),
            onPressed: _incrementCounter,
          ),
        ],
      ),
    );
  }
}

class BusinessTab extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return Center(
      child: Text(
        'Business Tab',
        style: TextStyle(fontSize: 24),
      ),
    );
  }
}

class SchoolTab extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return Center(
      child: Text(
        'School Tab',
        style: TextStyle(fontSize: 24),
      ),
    );
  }
}