Question

我无法使用Google Maps API版本3在Google地图上绘制多个标记。我正确加载了地图，并且XML Feed也正常运行。我无法使用javascript来绘制标记。

这是我的脚本标记。（主要取自Google教程）

<script type="text/javascript">

        function downloadUrl(url,callback) {

            var request = window.ActiveXObject ?
            new ActiveXObject('Microsoft.XMLHTTP') :
            new XMLHttpRequest;

            request.onreadystatechange = function() {
                if (request.readyState == 4) {
                    request.onreadystatechange = doNothing;
                    callback(request, request.status);
                }
            };

            request.open('GET', url, true);
            request.send(null);
        }

        function initialize() {

            var mapOptions = {
                center: new google.maps.LatLng(54.600035, -3.680419),
                zoom: 6
            };

            var map = new google.maps.Map(document.getElementById("map-holder"), mapOptions);
        }

        google.maps.event.addDomListener(window, 'load', initialize);

        downloadUrl("http://abcde.co.uk/xml-feed.php", function(data) {

                var xml = data.responseXML;
                var markers = xml.documentElement.getElementsByTagName("marker");

                for (var i = 0; i < markers.length; i++) {

                    var name = markers[i].getAttribute("name");
                    var address = markers[i].getAttribute("address");
                    var type = markers[i].getAttribute("type");

                    var point = new google.maps.LatLng(
                        parseFloat(markers[i].getAttribute("lat")),
                        parseFloat(markers[i].getAttribute("lng")));

                    var html = "<b>" + name + "</b> <br/>" + address;
                    var icon = customIcons[type] || {};

                    var marker = new google.maps.Marker({
                        map: map,
                        position: point,
                        icon: 'http://maps.google.com/mapfiles/ms/icons/green-dot.png'
                    });

                    bindInfoWindow(marker, map, infoWindow, html);
                }
            });

    </script>

我出错的任何想法？

XML响应看起来像这样......

 <markers>
 <marker name="name1" address="NW5 1JB" lat="51.560184" lng="-0.141326" type="Client" />
 <marker name="name2" address="NG18 1QH" lat="53.146017" lng="-1.203534" type="Client" />
 <marker name="name3" address="DN22 6NF" lat="53.321757" lng="-0.933399" type="Client" />
 </markers>

Answer 1

我认为您的变量map是在initialize函数内创建的。这意味着它的范围仅限于该函数：一旦它返回，map“死亡”。

您需要对map函数内的代码显示downloadUrl。您可以将调用移至downloadUrl函数内的initialize，也可以提前声明地图。如果选择后者，请注意downloadUrl函数完成之前initialize上的回调不会发生。

Answer 2

您的代码中存在许多javascript错误。当我修复它们（并使用稍微不同的downloadUrl版本）时，它对我有用。

<script type="text/javascript">

function bindInfoWindow(marker, map, infoWindow, html) {
  google.maps.event.addListener(marker, 'click', function() {
    infoWindow.setContent(html);
    infoWindow.open(map, marker);
  });
}

function initialize() {

  var mapOptions = {
        center: new google.maps.LatLng(54.600035, -3.680419),
        zoom: 6
      };

  var map = new google.maps.Map(document.getElementById("map-holder"), mapOptions);
  var bounds = new google.maps.LatLngBounds();
  var infoWindow = new google.maps.InfoWindow;

  downloadUrl("SO_markers_20140309.xml", function(data) {

    var xml = xmlParse(data);
    var markers = xml.documentElement.getElementsByTagName("marker");

    for (var i = 0; i < markers.length; i++) {

       var name = markers[i].getAttribute("name");
       var address = markers[i].getAttribute("address");
       var type = markers[i].getAttribute("type");

       var point = new google.maps.LatLng(
                        parseFloat(markers[i].getAttribute("lat")),
                        parseFloat(markers[i].getAttribute("lng")));

       bounds.extend(point);

       var html = "<b>" + name + "</b> <br/>" + address;
       // var icon = customIcons[type] || {};

       var marker = new google.maps.Marker({
                        map: map,
                        position: point,
                        icon: 'http://maps.google.com/mapfiles/ms/icons/green-dot.png'
                    });

       bindInfoWindow(marker, map, infoWindow, html);
     }
     map.fitBounds(bounds);
   });
 }

 google.maps.event.addDomListener(window, 'load', initialize);


 </script>

Working example

无法从XML Feed中绘制多个标记

2 个答案: