我正在开发一个OpenLayers地图,它将同时显示多个KML图层.我希望能够点击任何图层中的某个功能,并弹出一个向我显示的信息.到目前为止,我只能点击最近添加的图层.如果我想点击之前添加的图层,我必须关闭之前添加的所有图层.显然这不太理想.到目前为止,这是我的代码：
var select = [];
function addLayer(layerId,layerLink,layerColor)
{
var kmlLayer = new OpenLayers.Layer.Vector("Layer_"+layerId,{
strategies: [new OpenLayers.Strategy.Fixed()],protocol: new OpenLayers.Protocol.HTTP({
url: layerLink,format: new OpenLayers.Format.KML({
extractStyles: true,extractAttributes: true,maxDepth: 2
})
})
});
kmlLayer.events.on({
"featureselected": onKMLSelect,"featureunselected": onKMLUnselect
});
select["Layer_"+layerId] = new OpenLayers.Control.SelectFeature(kmlLayer);
map.addControl(select["Layer_"+layerId]);
select["Layer_"+layerId].activate();
map.addLayer(kmlLayer);
}
function onKMLPopupClose(evt) {
for(s in select)
{
select[s].unselectAll();
}
}
function onKMLSelect(event) {
var feature = event.feature;
var content = "<h2>"+feature.attributes.name + "</h2>" + feature.attributes.description;
popup = new OpenLayers.Popup.FramedCloud("chicken",feature.geometry.getBounds().getCenterLonLat(),new OpenLayers.Size(100,100),content,null,true,onKMLPopupClose);
feature.popup = popup;
map.addPopup(popup);
}
function onKMLUnselect(event) {
var feature = event.feature;
if(feature.popup) {
map.removePopup(feature.popup);
feature.popup.destroy();
delete feature.popup;
}
}
任何帮助将不胜感激.
谢谢,
解决方法
我刚才有同样的问题.你可以在
Openlayers Examples：
OpenLayers Select Feature on Multiple Layers Example找到一个很好的例子.
以下是代码的主要部分：
var map,selectControl;
function init(){
map = new OpenLayers.Map('map');
var wmsLayer = new OpenLayers.Layer.WMS(
"OpenLayers WMS","http://vmap0.tiles.osgeo.org/wms/vmap0",{layers: 'basic'}
);
var vectors1 = new OpenLayers.Layer.Vector("Vector Layer 1");
var vectors2 = new OpenLayers.Layer.Vector("Vector Layer 2");
map.addLayers([wmsLayer,vectors1,vectors2]);
map.addControl(new OpenLayers.Control.LayerSwitcher());
selectControl = new OpenLayers.Control.SelectFeature(
[vectors1,vectors2]
);
map.addControl(selectControl);
selectControl.activate();
map.setCenter(new OpenLayers.LonLat(0,0),3);
vectors1.addFeatures(createFeatures());
vectors2.addFeatures(createFeatures());
vectors1.events.on({
"featureselected": function(e) {
showStatus("selected feature "+e.feature.id+" on Vector Layer 1");
},"featureunselected": function(e) {
showStatus("unselected feature "+e.feature.id+" on Vector Layer 1");
}
});
vectors2.events.on({
"featureselected": function(e) {
showStatus("selected feature "+e.feature.id+" on Vector Layer 2");
},"featureunselected": function(e) {
showStatus("unselected feature "+e.feature.id+" on Vector Layer 2");
}
});
}