openlayers加载动态ArcGIS服务

openlayers加载ArcGIS动态服务图层ArcGISDanymicLayer

//arcgis动态图层服务地址
var url = 'https://sampleserver1.arcgisonline.com/ArcGIS/rest/services/' +
'Specialty/ESRI_StateCityHighway_USA/MapServer';
//创建动态图层
var danymicLayer=new ol.layer.Image({
          source: new ol.source.ImageArcGISRest({
            ratio: 1,
            params: {},
            url: url
          })
        })
//初始化地图
var map = new ol.Map({
        layers: [
          new ol.layer.Tile({
          source: new ol.source.OSM()
        })
       ],
        target: 'map',
        view: new ol.View({
          center: [-10997148, 4569099],
          zoom: 4
        })
      });
map.addLayer(danymicLayer);