如何在返回导航时再次显示BottomNavigationBar

import 'package:flutter/material.dart';

class MyPage extends StatefulWidget {
  @override
  _MyPageState createState() => _MyPageState();
}

class _MyPageState extends State<MyPage> {
  bool showBottomNavigationBar = true;

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text('My Page'),
      ),
      body: Column(
        children: [
          // 页面内容
        ],
      ),
      bottomNavigationBar: showBottomNavigationBar
          ? BottomNavigationBar(
              // BottomNavigationBar的配置
            )
          : null,
    );
  }

  @override
  void didChangeDependencies() {
    super.didChangeDependencies();
    // 监听路由变化
    RouteObserver routeObserver = RouteObserver<PageRoute>();
    routeObserver.subscribe(this, ModalRoute.of(context));
  }

  @override
  void didPopNext() {
    super.didPopNext();
    // 当页面从后台返回时，显示BottomNavigationBar
    setState(() {
      showBottomNavigationBar = true;
    });
  }
}