关于javascript:ArcGIS-for-JS-argis地图限制显示不规则区域

ArcGIS for JS argis地图限度显示不规则区域

   dojoRequire(["esri/map",     "esri/geometry/Point",    "esri/layers/ImageParameters",    "esri/layers/ArcGISDynamicMapServiceLayer",    "esri/layers/GraphicsLayer", ], (Map, Point, ImageParameters, ArcGISDynamicMapServiceLayer,GraphicsLayer) => {              //办法一   var    map = new Map("map", {        basemap: "satellite",         center: [113.36112, 23.12467],        zoom: 11,    });                       var imageParameters = new ImageParameters();    imageParameters.format = "PNG24";    var dynamicMapServiceLayer = new ArcGISDynamicMapServiceLayer("http://cache1.arcgisonline.cn/arcgis/rest/services/ChinaOnlineCommunity/MapServer", {      "opacity"        :1.0,      "imageParameters":imageParameters    });    map.addLayer(dynamicMapServiceLayer);    var canvas=document.getElementById("myCanvas");    var context=canvas.getContext("2d");    canvas.width = width    canvas.height = height    context.fillStyle="#fff";    context.fillRect(0,0,width,height);    axios.get(`/borderAll/test.json`).then(                   function (gzJson) {            var data=gzJson.data;            context.globalCompositeOperation='destination-out';            for (var item of data) {                var [lon, lat] = item                var [left,top] = this.lngLat2Vector2(lon,lat)                context.lineTo(left, top);            }            context.fillStyle="green";            context.fill();        }.bind(this)    );    })<div>             <div id='map' style={{height:window.innerHeight-50,width:'100%',position:'relative'}}></div>             <canvas id="myCanvas" className='shadediv' />        </div>

test.json为不规则门路的边界经纬度