Question

OpenLayers是否包含一个函数来根据它的ID返回标记引用？这是我想要工作的代码片段（我用注释标记为“HERE！”）：我试图使用命令“getMarkerById（this.id）”检索标记，并且firebug通知我返回价值未定义。然后我尝试使用其中一个标记（“41014”）的静态ID号，但也没有用。任何帮助将不胜感激！

$(function()
{
        var map, layer;


        //alert("RAN!!");

        map = new OpenLayers.Map("map");
        var wms = new OpenLayers.Layer.WMS(
        "OpenLayers WMS",
        "http://vmap0.tiles.osgeo.org/wms/vmap0",
        {'layers':'basic'} );
        map.addLayer(wms);
        map.setCenter(new OpenLayers.LonLat(-40, 30), 2.5);
        var markers = new OpenLayers.Layer.Markers("Markers");
        map.addLayer(markers);


        //load and retrieve values from local XML file here
    var xmlDoc=loadXMLDoc("http://whxlab3.dart.ns.ec.gc.ca/~brinka/EMETsiteV1/buoys.xml");
    var z=xmlDoc.getElementsByTagName("id");
    var y=xmlDoc.getElementsByTagName("lat");
    var x=xmlDoc.getElementsByTagName("lng");

    for(i=0; i<x.length; i++)
    {
        //use loaded XML file to retrieve values for marker positions
        var px = x[i].childNodes[0].nodeValue;
        var py = y[i].childNodes[0].nodeValue;
        var pz = z[i].childNodes[0].nodeValue;
        var size = new OpenLayers.Size(32, 37);
        var offset = new OpenLayers.Pixel(-(size.w/2), -size.h);
        var icon = new OpenLayers.Icon('stock_images/buoy.png', size, offset);
        icon.setOpacity(0.85);


        var lonlat = new OpenLayers.LonLat(px, py);

        var marker = new OpenLayers.Marker(lonlat, icon);
        marker.id=(pz);

        marker.events.register("mouseover", marker, function(){
            console.log("Over the marker "+this.id+" at place "+this.lonlat);
            this.inflate(1.2);
            this.setOpacity(1);
        });

        marker.events.register("mouseout", marker, function(){
            console.log("Out the marker "+this.id+" at place "+this.lonlat);
            this.inflate(1/1.2);
            this.setOpacity(0.85);
        });
        marker.events.register("click", marker, function(){
            console.log("Clicked "+this.id+" at place "+this.lonlat);
            console.log("Z value here: ", this.id);
            popup = new OpenLayers.Popup.FramedCloud("chicken", this.lonlat, new OpenLayers.Size(200, 200), ("Buoy Number: "+this.id), null, true);

            map.addPopup(popup);
            markers.removeMarker(getMarkerById(this.id)); //HERE!
        });

        markers.addMarker(marker);

    }


});

Answer 1

没有，但您可以在（全局）对象中定义标记，如：

obj.marker = new OpenLayers.Marker(lonlat, icon);

而不是添加到标记图层（例如“标记”）：

markers.addMarker(obj.marker);

如果要删除它，请执行以下操作：

markers.removeMarker(obj.marker);

Answer 2

 map = new OpenLayers.Map("map");
        var wms = new OpenLayers.Layer.WMS(
        "OpenLayers WMS",
        "http://vmap0.tiles.osgeo.org/wms/vmap0",
        {'layers':'basic'} );
        map.addLayer(wms);
        map.setCenter(new OpenLayers.LonLat(-40, 30), 2.5);

标记图层添加（矢量）

 var markerlayer = new OpenLayers.Layer.Vector("Marker Layers", { 
            styleMap: new OpenLayers.StyleMap({
                    'default': {
                        externalGraphic: "stock_images/buoy.png",  
                        graphicWidth:32,//pixel
                        graphicHeight:37,//pixel
                        graphicOpacity:"${opacity}"
                    }
                })
            });
            map.addLayer(markerlayer); 

var xmlDoc=loadXMLDoc("http://whxlab3.dart.ns.ec.gc.ca/~brinka/EMETsiteV1/buoys.xml");
    var z=xmlDoc.getElementsByTagName("id");
    var y=xmlDoc.getElementsByTagName("lat");
    var x=xmlDoc.getElementsByTagName("lng");

有：

    for(i=0; i<x.length; i++)
            {
        var px = x[i].childNodes[0].nodeValue;
        var py = y[i].childNodes[0].nodeValue;
        var pz = z[i].childNodes[0].nodeValue;

         var lonlat = new OpenLayers.LonLat(px, py);
        var marker= new OpenLayers.Feature.Vector(new OpenLayers.Geometry.Point(lonlat.lon, lonlat.lat));
       // var marker= new OpenLayers.Feature.Vector(new OpenLayers.Geometry.Point(px, py));
marker.attributes = {
        opacity: "1"
};
        markerlayer.addFeatures([marker]);
        };

点击功能

    markercontrol = new OpenLayers.Control.SelectFeature(markerlayer, { eventListeners: { featurehighlighted: controlfunction } }) 
    map.addControl(markercontrol);


    function controlfunction(e) {
        var featureID = e.feature.id;
var marker = markerlayer.getFeatureById(featureID)
marker.attributes.opacity = '0.5';//opacity
markerlayer.removeFeatures(marker);//remove
    console.log(featureID);
    console.log(e);
    }

并查看悬停： http://dev.openlayers.org/releases/OpenLayers-2.8/doc/apidocs/files/OpenLayers/Control/SelectFeature-js.html

如果你知道它是id，是否有可能得到一个标记？

2 个答案: