angular - 如何在 ionic 2 应用程序中自动更新谷歌地图上的当前位置

Question

我是 ionic 2 native 的初学者。我使用本教程 ( http://www.joshmorony.com/ionic-2-how-to-use-google-maps-geolocation-video-tutorial/ ) 创建了一个简单的位置跟踪应用程序，我想在用户旅行时自动更新用户当前位置。我搜索了教程或任何资源来了解这一点。但我找不到任何东西。如果有人知道 ioinc 2 中的自动更新用户位置，请告诉我该怎么做或给我一个链接。

这是我的代码

export class MapPage {

  x: number = 0;
  y: number = 0;

  @ViewChild('map') mapElement: ElementRef;
  map: any;

  constructor(public navCtrl: NavController) {
    this.loadMap();
  }

  loadMap() {
    Geolocation.getCurrentPosition().then((position) => {

      let latLng = new google.maps.LatLng(position.coords.latitude, position.coords.longitude);
      console.log(position.coords.latitude + " " + position.coords.longitude)
      let mapOptions = {
        center: latLng,
        zoom: 15,
        mapTypeId: google.maps.MapTypeId.ROADMAP
      }

      this.map = new google.maps.Map(this.mapElement.nativeElement, mapOptions);

      console.log(this.map);

    }, (err) => {
      console.log(err);
    });
  }

  addInfoWindow(marker, content) {

    let infoWindow = new google.maps.InfoWindow({
      content: content
    });

    google.maps.event.addListener(marker, 'click', () => {
      infoWindow.open(this.map, marker);
    });

  }

  showMyLocation() {

    Geolocation.getCurrentPosition().then((position) => {

      let latLng = new google.maps.LatLng(this.x, this.y);

      let marker = new google.maps.Marker({
        map: this.map,
        icon: new google.maps.MarkerImage('//maps.gstatic.com/mapfiles/mobile/mobileimgs2.png',
          new google.maps.Size(22, 22),
          new google.maps.Point(0, 18),
          new google.maps.Point(11, 11)),
        position: latLng
      });

      let content = "<h4>You are here</h4>";
      this.addInfoWindow(marker, content);

    }, (err) => {
      console.log(err);
    });
  }
}

这是HTML文件

<ion-header>
  <ion-navbar>
    <ion-title>
      Map
    </ion-title>
    <ion-input type=number style="border: 1px solid black" [(ngModel)]="x"></ion-input>
    <ion-input type=number style="border: 1px solid black" [(ngModel)]="y"></ion-input>
    <ion-buttons end>
      <button ion-button (click)="showMyLocation()"><ion-icon name="add"></ion-icon>Show my location</button>
    </ion-buttons>
  </ion-navbar>
</ion-header>

<ion-content>
  <div #map id="map"></div>
</ion-content>

谢谢

Answer 1

只需使用方法 watchPosition 而不是 getCurrentPosition :

 Geolocation.watchPosition().subscribe((position) => {
  this.x = position.coords.longitude;
  this.y = position.coords.latitude;

  let latLng = new google.maps.LatLng(this.x, this.y);

  let marker = new google.maps.Marker({
    map: this.map,
    icon: new google.maps.MarkerImage('//maps.gstatic.com/mapfiles/mobile/mobileimgs2.png',
      new google.maps.Size(22, 22),
      new google.maps.Point(0, 18),
      new google.maps.Point(11, 11)),
    position: latLng
  });

  let content = "<h4>You are here</h4>";
  this.addInfoWindow(marker, content);

}, (err) => {
  console.log(err);
});
}

请参阅此处 https://ionicframework.com/docs/v2/native/geolocation/在这里 https://github.com/apache/cordova-plugin-geolocation#navigatorgeolocationwatchposition了解更多详情。