如何在flutter中获取屏幕上的地图数据

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

class MapScreen extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text('Map Screen'),
      ),
      body: FlutterMap(
        options: MapOptions(
          center: LatLng(37.7749, -122.4194), // 地图中心点坐标
          zoom: 13.0, // 缩放级别
        ),
        layers: [
          TileLayerOptions(
            urlTemplate: 'https://{s}.tile.openstreetmap.org/{z}/{x}/{y}.png',
            subdomains: ['a', 'b', 'c'],
          ),
          MarkerLayerOptions(
            markers: [
              Marker(
                width: 80.0,
                height: 80.0,
                point: LatLng(37.7749, -122.4194), // 标记点坐标
                builder: (ctx) => Container(
                  child: FlutterLogo(),
                ),
              ),
            ],
          ),
        ],
      ),
    );
  }
}