如何使用Flutter/Dart在地图上添加标记点击/点击？

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

class MapScreen extends StatefulWidget {
  @override
  _MapScreenState createState() => _MapScreenState();
}

class _MapScreenState extends State<MapScreen> {
  GoogleMapController mapController;
  Set<Marker> markers = {};

  void _onMapCreated(GoogleMapController controller) {
    mapController = controller;
  }

  void _addMarker(LatLng position) {
    setState(() {
      markers.add(
        Marker(
          markerId: MarkerId(position.toString()),
          position: position,
          onTap: () {
            // 处理标记点击事件
            print('Marker tapped!');
          },
        ),
      );
    });
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text('Map Example'),
      ),
      body: GoogleMap(
        onMapCreated: _onMapCreated,
        markers: markers,
        initialCameraPosition: CameraPosition(
          target: LatLng(37.42796133580664, -122.085749655962),
          zoom: 10,
        ),
      ),
      floatingActionButton: FloatingActionButton(
        onPressed: () {
          _addMarker(LatLng(37.42796133580664, -122.085749655962));
        },
        child: Icon(Icons.add),
      ),
    );
  }
}