openLayer4实现动态改变标注图标

/初始化地图/
  var map;
  function initmap(){   
   map= new ol.Map({
   layers: layers,
   target: 'mapContainer',
   view: new ol.View({
    //地图中心坐标
    center: new ol.proj.fromLonLat([117.191166, 34.289749],'EPSG:3857'),
    zoom: 13//地图缩放级别
   })
   });
   //添加标注
   addFeature();      
  }



  /添加标注信息/
  function addFeature(){ 
  //数据太多，放json里读取，里面是标注的坐标信息  
  $.get('./featureData.json').done(function(data){ 
   var data = eval(data);
   var lon = 0;
   var lat = 0;
   var romeArr = [];
   for(var i=0;i<data .length;i++){
    lon = parseFloat(data [i].lon);
    lat = parseFloat(data [i].lat);
    name = data[i].name;    
    var rome = new ol.Feature({
     geometry:new ol.geom.Point(new ol.proj.fromLonLat([lon,lat],'EPSG:3857')),
     name:name
    });
    //标注样式设置
    rome.setStyle(new ol.style.Style({
     image: new ol.style.Icon(({
     crossOrigin: 'anonymous',
     scale:0.3, //标注图标大小     
     src: 'images/vtourskin_mapspot.png'
     }))
    }));
    romeArr.push(rome);  
   }
   //定义select控制器，点击标注后的事件
   var select= new ol.interaction.Select();
    //map加载该控件，默认是激活可用的
    map.addInteraction(select);
    select.on('select', function(e) {
    /恢复其他图标样式/
    romeArr.forEach(function(ele){
     ele.setStyle(new ol.style.Style({
     image: new ol.style.Icon(({
      crossOrigin: 'anonymous',
      scale:0.3,     
      src: 'images/vtourskin_mapspot.png'
     }))
     }));
    })
    console.log(e.selected); //打印已选择的Feature            
    /当前选择的图标变化，在此仅改变了图片路径以显示不同的图标，可以根据自己的需要进行设置/
    var currentRome = e.selected[0];
    currentRome.setStyle(new ol.style.Style({
     image: new ol.style.Icon(({
      crossOrigin: 'anonymous',
      scale:0.3,     
      src: 'images/vtourskin_mapspotactive.png'
     }))
     }));
    });

   vectorSource = new ol.source.Vector({
    features: romeArr
   });

   var vectorLayer = new ol.layer.Vector({
    source: vectorSource
   });

   map.addLayer(vectorLayer);

  });
}