High accuracy geolocation Html5

问题:

I am tring to locate a device using the embedded GPS (like whats app share location). I've read that it is possible with EnableHighAccuracy: true.

How can I set "enableHighAccuracy: true" in this code? I tried in different positions but it doesn't work.

<script type="text/javascript">
    if (navigator.geolocation) {
        navigator.geolocation.getCurrentPosition(function(position){
        var latitude = position.coords.latitude;
        var longitude = position.coords.longitude;
        var accuracy = position.coords.accuracy;
        var coords = new google.maps.LatLng(latitude, longitude);
        var mapOptions = {
            zoom: 15,
            center: coords,
            mapTypeControl: true,
            navigationControlOptions: {
                style: google.maps.NavigationControlStyle.SMALL
            },
            mapTypeId: google.maps.MapTypeId.ROADMAP
            };

         var capa = document.getElementById("capa");
         capa.innerHTML = "latitud: " + latitude + " longitud: " + "   aquesta es la precisio en metres  :  " + accuracy;  

            map = new google.maps.Map(
                document.getElementById("mapContainer"), mapOptions
                );
            var marker = new google.maps.Marker({
                    position: coords,
                    map: map,
                    title: "ok"
            });


        });

    }else {
        alert("Geolocation API is not supported in your browser.");
    }

</script>

Thanks a lot!

回答1:

You need a PositionOptions object, in which you set the high accuracy flag following the API.

I am quoting from here: http://diveintohtml5.info/geolocation.html

The getCurrentPosition() function has an optional third argument, a PositionOptions object. There are three properties you can set in a PositionOptions object. All the properties are optional. You can set any or all or none of them.

POSITIONOPTIONS OBJECT

Property            Type        Default     Notes
--------------------------------------------------------------
enableHighAccuracy  Boolean     false       true might be slower
timeout             long    (no default)    in milliseconds
maximumAge              long    0               in milliseconds

So, it should work like this:

if (navigator.geolocation) {
    navigator.geolocation.getCurrentPosition(function(position){
    var latitude = position.coords.latitude;
    var longitude = position.coords.longitude;
    var accuracy = position.coords.accuracy;
    var coords = new google.maps.LatLng(latitude, longitude);
    var mapOptions = {
        zoom: 15,
        center: coords,
        mapTypeControl: true,
        navigationControlOptions: {
            style: google.maps.NavigationControlStyle.SMALL
        },
        mapTypeId: google.maps.MapTypeId.ROADMAP
        };

     var capa = document.getElementById("capa");
     capa.innerHTML = "latitud: " + latitude + " longitud: " + "   aquesta es la precisio en metres  :  " + accuracy;  

        map = new google.maps.Map(
            document.getElementById("mapContainer"), mapOptions
            );
        var marker = new google.maps.Marker({
                position: coords,
                map: map,
                title: "ok"
        });


    },function error(msg){alert('Please enable your GPS position future.');  

  }, {maximumAge:600000, timeout:5000, enableHighAccuracy: true});

}else {
    alert("Geolocation API is not supported in your browser.");
}

Noticed I added the following 2 params to getCurrentPosition call:

,function error(msg){alert('Please enable your GPS position future.');}  

, {maximumAge:600000, timeout:5000, enableHighAccuracy: true});

Also see: Geolocation HTML5 enableHighAccuracy True , False or Best Option?

回答2:

Here's a simple example of enableHighAccuracy: true

var options = {
  enableHighAccuracy: true,
  timeout: 5000,
  maximumAge: 0
};

function success(pos) {
  var crd = pos.coords;

  console.log('Your current position is:');
  console.log(`Latitude : ${crd.latitude}`);
  console.log(`Longitude: ${crd.longitude}`);
  console.log(`More or less ${crd.accuracy} meters.`);
}

function error(err) {
  console.warn(`ERROR(${err.code}): ${err.message}`);
}

navigator.geolocation.getCurrentPosition(success, error, options);

The above example is from the Mozilla Developer Network.