如何在颤振中保留导航栏

Question

我在进入下一页时如何保留导航栏有问题，我一直在使用 curved_navigation_bar，当我点击仪表板栏时，它会转到下一页，但是问题是导航栏根本没有保留。如果有人能弄清楚就太好了，在此先感谢您！

导航栏页面

Color color = Colors.deepOrangeAccent;
String disp ='';
class HomePage extends State<MyHomePage>{
  @override
  Widget build(BuildContext context){
    return Scaffold(
      backgroundColor: color,
      bottomNavigationBar: CurvedNavigationBar(
        backgroundColor: color,
        items: [
          Icon(Icons.home),
          Icon(Icons.dashboard),
          Icon(Icons.settings)
        ],
        onTap: (index){
          setState(() {
            if (index ==0){
              disp = 'Home';
              color = Colors.blueGrey;
            }
            else if (index ==1){
              disp = 'Dashboard';
              color = Colors.orange;
              Navigator.push(context, MaterialPageRoute(
                builder: (context) =>GoogleMapScreen(),
              ),);
             //----- Execute to Another Page -------
            }
            else{
              disp = 'Settings';
              color = Colors.green;
            }
          });
        },
      ),
    );
  }
}

GoogleMapScreen 页面

import 'package:flutter/material.dart';
import 'package:google_maps_flutter/google_maps_flutter.dart';

class GoogleMapScreen extends StatefulWidget{
  @override
  _GoogleMapScreenState createState() => _GoogleMapScreenState();
}
class _GoogleMapScreenState extends State<GoogleMapScreen>{
  Set<Marker> _markers = {};
  void _onMapCreated(GoogleMapController controller) {
    setState(() {
      _markers.add(
        Marker(markerId: MarkerId('id-1'),
          position:  LatLng(8.9475, 125.5406),
          infoWindow: InfoWindow(
            title: 'Mackys house',
            snippet: 'A secret Place',
          )
        ),
      );
    });
  }
  @override
  Widget build(BuildContext context){
    return Scaffold(
        appBar: AppBar(
          title: Text('Google Map'),
        ),
        body: GoogleMap(
            onMapCreated:  _onMapCreated,
            markers: _markers,
            initialCameraPosition: CameraPosition(target: LatLng(0.0000, 000.0000),
              zoom: 15,
            ))
         );
       }
     }

Answer 1

更新：

Widget _content = Container();
Color color = Colors.deepOrangeAccent;
String disp ='';
class HomePage extends State<MyHomePage>{
  @override
  Widget build(BuildContext context){
    return Scaffold(
      backgroundColor: color,
      body: _content,
      bottomNavigationBar: CurvedNavigationBar(
        backgroundColor: color,
        items: [
          Icon(Icons.home),
          Icon(Icons.dashboard),
          Icon(Icons.settings)
        ],
        onTap: (index){
          setState(() {
            if (index ==0){
              _content = Container();
            }
            else if (index ==1){
              _content = GoogleMapScreen();
            }
            else{
              _content = Container();
            }
          });
        },
      ),
    );
  }
}