如何在bottomNavigationBar选项卡中传递变量

import 'package:flutter/material.dart';

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

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'BottomNavigationBar传递变量示例',
      theme: ThemeData(
        primarySwatch: Colors.blue,
      ),
      home: MyHomePage(),
    );
  }
}

class MyHomePage extends StatefulWidget {
  @override
  _MyHomePageState createState() => _MyHomePageState();
}

class _MyHomePageState extends State<MyHomePage> {
  int _currentIndex = 0;
  String _selectedTab = '';

  void _onTabTapped(int index) {
    setState(() {
      _currentIndex = index;
      _selectedTab = '选项卡$index';
    });
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text('BottomNavigationBar传递变量示例'),
      ),
      body: Center(
        child: Text('当前选中的选项卡是：$_selectedTab'),
      ),
      bottomNavigationBar: BottomNavigationBar(
        currentIndex: _currentIndex,
        onTap: _onTabTapped,
        items: [
          BottomNavigationBarItem(
            icon: Icon(Icons.home),
            label: '首页',
          ),
          BottomNavigationBarItem(
            icon: Icon(Icons.search),
            label: '搜索',
          ),
          BottomNavigationBarItem(
            icon: Icon(Icons.person),
            label: '个人中心',
          ),
        ],
      ),
    );
  }
}