OpenLayers 3 版本:OpenLayers v4.3.2
想通過屬性查詢feature,但是在ol3中並沒有發現類似ol2中的getFeatureByAttribute()....
自己寫函數實現,實現方法如下:
var layer = new ol.layer.Vector({ source: new ol.source.Vector({ features:ol.Feature, url: './resources/data/test.geojson', format: new ol.format.GeoJSON() }), style:polygonStyle }); map.addLayer(layer);
function selectByAttribute(){ var features = layer.getSource().getFeatures(); //console.log(features); var value = '115街坊'; var property = 'name';
var selectedByAttriFeature;//實際應用中設置成全局變量 for (var i = 0, ii = features.length; i < ii; i++) { if (features[i].get(property) === value) { selectedByAttriFeature = features[i]; break; } } selectedByAttriFeature.setStyle(featureSelectStyle);//高亮查詢到的feature //console.log(selectedByAttriFeature.getGeometry().A);//后台輸出發現,geometry屬性中有一個屬性A其實是中心點坐標,但是沒有提供獲取中心點的方法,.getGeometry().A也可獲得中心點 //console.log(getCenterOfExtent(selectedByAttriFeature.getGeometry().getExtent()));//結果同上 var my_view = new ol.View({ center: getCenterOfExtent(selectedByAttriFeature.getGeometry().getExtent()), zoom: 14 }); map.setView(my_view); }
獲得feature的中心點坐標:【偶然發現ol3有方法獲得中心點坐標:ol.extent.getCenter(selectedFeature.getGeometry().getExtent())】
function getCenterOfExtent(Extent){ var X = Extent[0] + (Extent[2]-Extent[0])/2; var Y = Extent[1] + (Extent[3]-Extent[1])/2; return [X, Y]; }
清除已經選擇的高亮feature:
function clearSelectByAttribute(){ if(selectedByAttriFeature != null){ selectedByAttriFeature.setStyle(null); selectedByAttriFeature = null; } }