google maps api v3上搜索到的地址与最近的现有地标之间的距离

Question

我正在使用 Google Maps API v3 开发网页。我目前有一个功能地图和搜索栏。我需要能够在地图上的一个 KML 文件上显示从搜索地址到最近地标的距离。我该怎么做？

这是页面的代码：

<script type="text/javascript">
    var geocoder;
    var map; 
    var marker;
    var layers = [];
  function initialize() {
    geocoder = new google.maps.Geocoder ();
    var latlng = new google.maps.LatLng (41, -73.4);
    var myOptions = {
      zoom: 7,
      center: latlng,
      mapTypeId: google.maps.MapTypeId.ROADMAP
        }
      map = new google.maps.Map(document.getElementById("map_canvas"),
        myOptions);
      marker = new google.maps.Marker({map:map});


        layers[0] = new google.maps.KmlLayer('http://dl.dropbox.com/u/80233620/South-and-North-County-Trailway.kml',
            {preserveViewport: true});
        layers[1] = new google.maps.KmlLayer('http://www.nyc.gov/html/dot/downloads/misc/cityracks.kml', 
            {preserveViewport: true});
        layers[2] = new google.maps.KmlLayer('http://dl.dropbox.com/u/80233620/NWS%20Radar%20Images.kmz', 
            {preserveViewport: true});
    for (var i = 0; i < layers.length; i++) {
                layers[i].setMap(map);
              }
        }

    function codeAddress () {
        var address = document.getElementById ("address").value;
        geocoder.geocode ( { 'address': address}, function(results, status)  {
        if (status == google.maps.GeocoderStatus.OK)  {
            map.setCenter(results [0].geometry.location);
            marker.setPosition(results [0].geometry.location);
            map.setZoom(14);
            } 
        else {
            alert("Geocode was not successful for the following reason: " + status);
                }
        }); 
                            }
    function toggleLayer(i) {
      if(layers[i].getMap() === null) {
        layers[i].setMap(map);
      }
      else {
        layers[i].setMap(null);}
    }

</script>

Answer 1

您不能像那样访问 KML 图层中的数据

https://developers.google.com/maps/documentation/javascript/layers#KMLLayers

由于 KML 可能包含大量功能，您可能无法访问 直接来自 KmlLayer 对象的特征数据。相反，作为特征 被显示，它们被渲染成看起来像可点击的 Maps API 覆盖。

相反，您可以手动处理 XML 并添加标记，然后使用 geometry library 和 computeDistanceBetween() 获取距离。我通常将距离乘以某个数字来计算转弯（距离公式得到直线距离）。我相信1.2 附近是最准确的。