在 openlayer 地图上每 5 秒更新一次位置

Question

我有一个 WebView 应用程序。我想每 5 秒更新一次我的位置。我是运行下面的代码，但是每次坐标更改时都会显示此代码。我正在将此数据保存在数据库中。我怎么解决这个问题？谢谢

const view = new ol.View({
  center: [0,0],
  zoom: 7,
  projection: 'EPSG:4326',
});

const map = new ol.Map({
  layers: [
    new ol.layer.Tile({
      source: new ol.source.OSM(),
    }),
  ],
  target: 'map',
  view: view,
});

const geolocation = new ol.Geolocation({
  trackingOptions: {
    enableHighAccuracy: true,
  },
  projection: view.getProjection(),
});

function el(id) {
  return document.getElementById(id);
}

geolocation.setTracking(1);

// update the HTML page when the position changes.
geolocation.on('change', function () {
  console.log(geolocation.getAccuracy() + ' [m]');
  console.log(geolocation.getAltitude() + ' [m]');
  console.log(geolocation.getAltitudeAccuracy() + ' [m]');
  console.log(geolocation.getHeading() + ' [rad]');
  console.log(geolocation.getSpeed() + ' [m/s]');
});

// handle geolocation error.
geolocation.on('error', function (error) {
  const info = document.getElementById('info');
  info.innerHTML = error.message;
  info.style.display = '';
});

const accuracyFeature = new ol.Feature();
geolocation.on('change:accuracyGeometry', function () {
  accuracyFeature.setGeometry(geolocation.getAccuracyGeometry());
});

const positionFeature = new ol.Feature();
positionFeature.setStyle(
  new ol.style.Style({
    image: new ol.style.Circle({
      radius: 6,
      fill: new ol.style.Fill({
        color: '#3399CC',
      }),
      stroke: new ol.style.Stroke({
        color: '#fff',
        width: 2,
      }),
    }),
  })
);

geolocation.on('change:position', function () {
  const coordinates = geolocation.getPosition();
  console.log(geolocation.getPosition());
  positionFeature.setGeometry(coordinates ? new ol.geom.Point(coordinates) : null);
});

new ol.layer.Vector({
  map: map,
  source: new ol.source.Vector({
    features: [accuracyFeature, positionFeature],
  }),
});

我从 openlayers 的网站上获得了这段代码。我所做的唯一更改：

geolocation.setTracking(1);

我想一打开地图就知道我的位置。但是太多的数据来了。我只想每 5 秒获取一次位置和更新点。

Answer 1

只要设备的 GPS 更新，就会触发 change:position 事件。要以固定间隔更新，只需以 5 秒间隔读取位置

setInterval(function () {
  const coordinates = geolocation.getPosition();
  console.log(geolocation.getPosition());
  positionFeature.setGeometry(coordinates ? new ol.geom.Point(coordinates) : null);
}, 5000);

在 openlayer 地图上每 5 秒更新一次位置

Location update every 5 seconds on openlayer map

javascript

geolocation

openlayers