HTML5 geolocation watchPosition 只被调用一次

Question

我正在使用 html 5 创建一个 android 应用程序，我想在用户移动时从用户那里访问 latlong。我使用过 watchPostion，但它只给我一次用户位置。

    var watchID;
var geoLoc;

function showLocation(position) {
  var latitude = position.coords.latitude;
  var longitude = position.coords.longitude;

    var ll=new google.maps.LatLng(latitude, longitude);
    map.setCenter(ll);

  console.log("Latitude : " + latitude + " Longitude: " + longitude);
}

function errorHandler(err) {
  if(err.code == 1) {
    console.log("Error: Access is denied!");
  }else if( err.code == 2) {
    console.log("Error: Position is unavailable!");
  }
    }
    if(navigator.geolocation){
      // timeout at 60000 milliseconds (60 seconds)
      var options = {timeout:60000};
      geoLoc = navigator.geolocation;
      watchID = geoLoc.watchPosition(showLocation, 
                                     errorHandler,
                                     options);


   }else{
      console.log("Sorry, browser does not support geolocation!");
   }

Answer 1

几个月前我一直在做类似的事情。我记得有同样的问题。也许这会有所帮助。

$(document).ready(function(){  
    initLocationProcedure();
}

function initLocationProcedure() {
    map = new google.maps.Map(document.getElementById('map_canvas'), {
          zoom : 17
    });

    if (navigator.geolocation) {
        navigator.geolocation.getCurrentPosition(displayAndWatch, locError, {
            enableHighAccuracy : true,
            timeout : 60000,
            maximumAge : 0
        });
    } else {
        alert("Your phone does not support the Geolocation API");
    }
}

function displayAndWatch(position) {
    // set current position
    setUserLocation(position);
    // watch position
    watchCurrentPosition();
}

function setUserLocation(pos) {
    // marker for userLocation
    userLocation = new google.maps.Marker({
           map : map,
           position : new google.maps.LatLng(pos.coords.latitude, pos.coords.longitude),
           title : "You are here",
           icon : "../img/user-location.svg",
    // scroll to userLocation
    map.panTo(new google.maps.LatLng(pos.coords.latitude, pos.coords.longitude));
});

这就是你要找的

function watchCurrentPosition() {
    var positionTimer = navigator.geolocation.watchPosition(function(position) {
        setMarkerPosition(userLocation, position);
        map.panTo(new google.maps.LatLng(position.coords.latitude, position.coords.longitude));
    });
}

function setMarkerPosition(marker, position) {
     marker.setPosition(new google.maps.LatLng(position.coords.latitude, position.coords.longitude));
     console.log(position);
}

fiddle
http://jsfiddle.net/XEFks/