使用google将api放置在设备当前位置附近的地方

Question

我正在使用Google maps API和Google Places API来获取用户设备的当前位置，并从该位置检索附近的餐馆，健身房等。我已经检查了官方的谷歌文档，我已经创建了这段代码：

HTML代码：

<div id="map">  </div>
<script src="https://maps.googleapis.com/maps/api/js?key=I_REPLACED_MY_KEY_IN_HERE&libraries=places&callback=initMap" async defer ></script>

JAVASCRIPT：

var map;
var service;
var infowindow;
var pos;
var request;
var place;

function initMap() {
  map = new google.maps.Map(document.getElementById('map'), {
    center: {lat: -34.397, lng: 150.644},
    zoom: 6
  });
  infoWindow = new google.maps.InfoWindow;

  getLocation();
  getNearByPlaces();
  callback();
}

  function getLocation(){
  // Try HTML5 geolocation.
  if (navigator.geolocation) {
    navigator.geolocation.getCurrentPosition(function(position) {
       pos = {
        lat: position.coords.latitude,
        lng: position.coords.longitude
      };

      infoWindow.setPosition(pos);
      infoWindow.setContent('Location found.');
      infoWindow.open(map);
      map.setCenter(pos);
    }, function() {
      handleLocationError(true, infoWindow, map.getCenter());
    });
  } else {
    // Browser doesn't support Geolocation
    handleLocationError(false, infoWindow, map.getCenter());
  }

infowindow = new google.maps.InfoWindow();
}

function getNearByPlaces(){
   request = {
    location: pos,
    radius: '500',
    query: 'restaurant'
  };

  service = new google.maps.places.PlacesService(map);
  service.textSearch(request, callback);
}

function callback(results, status){
  if (status == google.maps.places.PlacesServiceStatus.OK){
    for (var i =0; i<results.length; i++){
      place = results[i];
    }
  }
}

我正在获取附近地点和设备当前位置的地图，问题是我没有得到我在请求中指定的餐馆，我想获得仅在500范围内的餐馆并检索他们的纬度和经度，getnearbyplaces和回调都没有做任何事情。

Answer 1

地理定位服务是异步的。在位置可用时，您需要在地理定位服务的回调函数中调用getNearByPlaces。

function getLocation() {
  // Try HTML5 geolocation.
  if (navigator.geolocation) {
    navigator.geolocation.getCurrentPosition(function(position) {
      pos = {
        lat: position.coords.latitude,
        lng: position.coords.longitude
      };
      getNearByPlaces(pos); // depends on value of pos
   // existing error handling...

proof of concept fiddle

代码段：

var map;
var service;
var infowindow;
var pos;
var request;
var place;

function initMap() {
  map = new google.maps.Map(document.getElementById('map'), {
    center: {
      lat: -34.397,
      lng: 150.644
    },
    zoom: 6
  });
  infoWindow = new google.maps.InfoWindow;

  getLocation();
  // getNearByPlaces();
  // callback();
}

function getLocation() {
  // Try HTML5 geolocation.
  if (navigator.geolocation) {
    navigator.geolocation.getCurrentPosition(function(position) {
      pos = {
        lat: position.coords.latitude,
        lng: position.coords.longitude
      };
      console.log("getLocation:" + pos.lat + "," + pos.lng);
      var marker = new google.maps.Marker({
        position: pos,
        map: map,
        icon: "http://maps.google.com/mapfiles/ms/micons/blue.png"
      })
      infoWindow.setPosition(pos);
      infoWindow.setContent('Location found.');
      infoWindow.open(map);
      map.setCenter(pos);
      getNearByPlaces(pos);
    }, function() {
      console.log("calling handleLocationError(true)");
      handleLocationError(true, infoWindow, map.getCenter());
    });
  } else {
    // Browser doesn't support Geolocation
    console.log("calling handleLocationError(false)")
    handleLocationError(false, infoWindow, map.getCenter());
  }

  infowindow = new google.maps.InfoWindow();
}

function getNearByPlaces(pos) {
  console.log("getNearByPlaces:" + pos.lat + "," + pos.lng);
  request = {
    location: pos,
    radius: '500',
    query: 'restaurant'
  };

  service = new google.maps.places.PlacesService(map);
  service.textSearch(request, callback);
}

function callback(results, status) {
  if (status == google.maps.places.PlacesServiceStatus.OK) {
    console.log("callback received " + results.length + " results");
    var bounds = new google.maps.LatLngBounds();
    for (var i = 0; i < results.length; i++) {
      console.log(JSON.stringify(results[i]));
      place = results[i];
      var mark = createMarker(results[i]);
      bounds.extend(mark.getPosition());
    }
    map.fitBounds(bounds);
  } else console.log("callback.status=" + status);
}

function handleLocationError(browserHasGeolocation, infoWindow, pos) {
  infoWindow.setPosition(pos);
  infoWindow.setContent(browserHasGeolocation ?
    'Error: The Geolocation service failed.' :
    'Error: Your browser doesn\'t support geolocation.');
  infoWindow.open(map);
}

function createMarker(place) {
  var marker = new google.maps.Marker({
    map: map,
    position: place.geometry.location,
    icon: "http://maps.google.com/mapfiles/ms/micons/red.png"
  });

  google.maps.event.addListener(marker, 'click', function() {
    infowindow.setContent(place.name);
    infowindow.open(map, this);
  });
  return marker;
}

  html,
  body,
  #map {
    height: 100%;
    margin: 0;
    padding: 0;
  }

<div id="map"></div>
<!-- Replace the value of the key parameter with your own API key. -->
<script src="https://maps.googleapis.com/maps/api/js?key=AIzaSyCkUOdZ5y7hMm0yrcCQoCvLwzdM6M8s5qk&libraries=places&callback=initMap" async defer></script>