如何在flutter中从另一页地图中获取值

import 'package:flutter/material.dart';
import 'package:flutter_map/flutter_map.dart';
import 'package:latlong/latlong.dart';

class MapPage extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text('Map Page'),
      ),
      body: FlutterMap(
        options: MapOptions(
          center: LatLng(0, 0),
          zoom: 10.0,
        ),
        layers: [
          TileLayerOptions(
            urlTemplate: 'https://{s}.tile.openstreetmap.org/{z}/{x}/{y}.png',
            subdomains: ['a', 'b', 'c'],
          ),
        ],
      ),
      floatingActionButton: FloatingActionButton(
        onPressed: () {
          // 获取选择的位置信息
          LatLng selectedLocation = /* 获取选择的位置信息的方法 */;
          
          // 将位置信息传递回上一个页面
          Navigator.pop(context, selectedLocation);
        },
        child: Icon(Icons.check),
      ),
    );
  }
}

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

class _HomePageState extends State<HomePage> {
  LatLng selectedLocation; // 存储选择的位置信息

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text('Home Page'),
      ),
      body: Center(
        child: Column(
          mainAxisAlignment: MainAxisAlignment.center,
          children: [
            Text(
              'Selected Location:',
              style: TextStyle(fontSize: 20),
            ),
            Text(
              selectedLocation != null
                  ? 'Latitude: ${selectedLocation.latitude}, Longitude: ${selectedLocation.longitude}'
                  : 'No location selected',
              style: TextStyle(fontSize: 16),
            ),
          ],
        ),
      ),
      floatingActionButton: FloatingActionButton(
        onPressed: () {
          // 打开地图页面
          Navigator.push(
            context,
            MaterialPageRoute(
              builder: (context) => MapPage(),
            ),
          ).then((value) {
            // 接收传递回来的位置信息
            setState(() {
              selectedLocation = value;
            });
          });
        },
        child: Icon(Icons.map),
      ),
    );
  }
}

void main() {
  runApp(MaterialApp(
    home: HomePage(),
  ));
}