在谷歌地图中添加标记时IONIC V4应用程序关闭

import { Component, OnInit } from '@angular/core';
import { GoogleMap, GoogleMaps, GoogleMapOptions, Marker } from '@ionic-native/google-maps';

@Component({
  selector: 'app-map',
  templateUrl: './map.page.html',
  styleUrls: ['./map.page.scss'],
})
export class MapPage implements OnInit {
  map: GoogleMap;
  marker: Marker;

  ngOnInit() {
    this.loadMap();
  }

  loadMap() {
    const mapOptions: GoogleMapOptions = {
      camera: {
        target: {
          lat: 37.4219999,
          lng: -122.0840575
        },
        zoom: 10,
      }
    };

    this.map = GoogleMaps.create('map_canvas', mapOptions);

    this.addMarker();
  }

  addMarker() {
    const markerOptions = {
      position: {
        lat: 37.4219999,
        lng: -122.0840575
      },
      title: 'My Marker'
    };

    this.marker = this.map.addMarkerSync(markerOptions);

    // 关闭地图时隐藏标记
    this.map.on(GoogleMapsEvent.MAP_CLOSE).subscribe(() => {
      this.marker.setVisible(false);
    });
  }
}