Flutter，如何删除导航中的后退按钮？

登录后我的Homepage.dart里有这段代码，不知能否去掉导航栏中的后退按钮，请看下图

import 'package:flutter/material.dart';

class HomePage extends StatefulWidget {
  @override
  _HomePageState createState() => _HomePageState();
}

class _HomePageState extends State<HomePage> {
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text('My Flutter App'),
      ),
      bottomNavigationBar: BottomNavigationBar(
        currentIndex: 0, // this will be set when a new tab is tapped
        items: [
          BottomNavigationBarItem(
            icon: new Icon(Icons.home),
            title: new Text('Home'),
          ),
          BottomNavigationBarItem(
            icon: new Icon(Icons.mail),
            title: new Text('Messages'),
          ),
          BottomNavigationBarItem(
              icon: Icon(Icons.person),
              title: Text('Profile')
          )
        ],
      ),
    );
  }
}

我就是这样称呼主页的

onPressed: () {
    Navigator.push(context, MaterialPageRoute(builder: (_) => HomePage()));
} 

回答