底部导航嵌套索引问题

Question

我正在使用具有底部导航功能并为初始页面嵌套子页面的应用程序。问题是，当我进入嵌套页面，然后单击底部导航项时，我想重置堆栈，然后它应显示初始页面（在单击的任何项上）：

我已经编写了以下代码，但我无法实现这一目标。

import 'package:flutter/material.dart';

class NavigatorPage extends StatefulWidget {
  const NavigatorPage({Key key, this.child}) : super(key: key);

  final Widget child;

  @override
  _NavigatorPageState createState() => _NavigatorPageState();
}

class _NavigatorPageState extends State<NavigatorPage> {
  @override
  Widget build(BuildContext context) {
    return Navigator(
      onGenerateRoute: (RouteSettings settings) {
        return new MaterialPageRoute(
          settings: settings,
          builder: (BuildContext context) {
            return Center(
              child: Column(
                mainAxisSize: MainAxisSize.min,
                children: <Widget>[
                  widget.child,
                  SizedBox(height: 16.0),
                ],
              ),
            );
          },
        );
      },
    );
  }
}

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

class _HomePageState extends State<HomePage> {
  int _pageIndex = 0;

  @override
  Widget build(BuildContext context) {
    print(_pageIndex);
    return MaterialApp(
      home: Scaffold(
        body: SafeArea(
          child: IndexedStack(
            index: _pageIndex,
            children: const <Widget>[
              NavigatorPage(child: SampleClass()),
              NavigatorPage(child: Text('Business')),
              NavigatorPage(child: Text('School')),
            ],
          ),
        ),
        bottomNavigationBar: BottomNavigationBar(
          items: const <BottomNavigationBarItem>[
            BottomNavigationBarItem(icon: Icon(Icons.home), title: Text('')),
            BottomNavigationBarItem(
                icon: Icon(Icons.business), title: Text('')),
            BottomNavigationBarItem(icon: Icon(Icons.school), title: Text('')),
          ],
          currentIndex: _pageIndex,
          onTap: (int index) {
            setState(() {
              _pageIndex = index;
            });
          },
        ),
      ),
    );
  }
}

class SampleClass extends StatelessWidget {
  const SampleClass({Key key}) : super(key: key);

  @override
  Widget build(BuildContext context) {
    return Container(
      child: RaisedButton(
        child: Text('push a route'),
        onPressed: () {
          Navigator.of(context).push(MaterialPageRoute(
            builder: (BuildContext context) {
              return NewSamplePageRoute();
            },
          ));
        },
      ),
    );
  }
}

class Page1 extends StatelessWidget {
  const Page1({Key key}) : super(key: key);

  @override
  Widget build(BuildContext context) {
    return Container(
      child: Text('asdfs'),
    );
  }
}

/*  */

class NewSamplePageRoute extends StatelessWidget {
  const NewSamplePageRoute({Key key}) : super(key: key);

  @override
  Widget build(BuildContext context) {
    return Container(
      child: RaisedButton(
        child: Text('push a route'),
        onPressed: () {
          Navigator.of(context).push(MaterialPageRoute(
            builder: (BuildContext context) {
              return Page1();
            },
          ));
        },
      ),
    );
  }
}

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

以下是该问题的示例Gig图像：