arcgis api for javascript之加载图层

图层种类有很多种：查看api

加载切片实例TileLayer

 <script>
    require([
        "esri/Map",
        "esri/views/SceneView",
        "esri/layers/TileLayer",
        "dojo/dom",
        "dojo/on",
        "dojo/domReady!"
      ],
      function(
        Map, SceneView, TileLayer, dom, on
      ) {

        /*****************************************************************
         定义图层
         *****************************************************************/
        var transportationLayer = new TileLayer({
          url: "https://server.arcgisonline.com/ArcGIS/rest/services/Reference/World_Transportation/MapServer",//arcgisserver切片图层地址      
          id: "streets",// 唯一id，指map中添加的图层id是唯一的
          visible: false//默认是否显示 
        });

        var housingLayer = new TileLayer({
          url: "https://tiles.arcgis.com/tiles/nGt4QxSblgDfeJn9/arcgis/rest/services/New_York_Housing_Density/MapServer",
          id: "ny-housing",
          opacity: 0.9//透明度
        });

        /*****************************************************************
         * 初始化Map时直接添加
         *****************************************************************/
        var map = new Map({
          basemap: "oceans",
          layers: [housingLayer]
        });

        /*****************************************************************
         * 通过Map对象的方法添加图层
         *****************************************************************/
        map.add(transportationLayer);

        var view = new SceneView({
          container: "viewDiv",
          map: map
        });

        /*****************************************************************
         监听地图视图初始化过程
         *****************************************************************/
        view.on("layerview-create", function(event) {
          if (event.layer.id === "ny-housing") {
            // 判断当前加载的图层属性
            console.log("LayerView for male population created!", event.layerView);
          }
          if (event.layer.id === "streets") {
            //判断当前加载的图层属性
            console.log("LayerView for streets created!", event.layerView);
          }
        });

        /*****************************************************************
         监听图层加载完成事件，缩放到图层范围
         *****************************************************************/
        view.when(function() {
          housingLayer.when(function() {//es6语法
            view.goTo(housingLayer.fullExtent);
          });
        });

        var streetsLayerToggle = dom.byId("streetsLayer");

        /*****************************************************************
         *控制图层显示与隐藏
         *******************************************************************/
        on(streetsLayerToggle, "change", function() {
          transportationLayer.visible = streetsLayerToggle.checked;
        });
      });
  </script>

不同图层具有独自的属性和方法以及适用的服务，按需进行选择。
比如加载ogc标准的其他地图服务的wms,wmts切片服务，加载大量点数据的PointCloudLayer图层等等