TextSymbol 在 MapView 中不起作用(ESRI 4.3 arcgis)

TextSymbol not working inside MapView(ESRI 4.3 arcgis)

以下是我的代码示例-

我尝试使用 Picture Marker Symbol(如示例中所用)渲染地图并且效果很好,但如果我使用 Graphic 对象中文档中提到的 TextSymbol,应用程序将失败并显示 TypeError 错误:无法读取未定义的 属性 'setTransform' 且 u 未定义。 有人可以帮我解决我做错的事吗?

    let mapProperties: any = {
        basemap: "streets",
        ground: "world-elevation"
      };

      let map: any = new Map(mapProperties);
      let constructMap = function (lat, long, popupTemplate) {
        var point = new Point({
          longitude: lat,
          latitude: long
        });
        var markerSymbol = new PictureMarkerSymbol({
          url: "https://unpkg.com/leaflet@1.0.3/dist/images/marker-icon.png",
          width: "25px",
          height: "41px"
        });


        var textSym = new TextSymbol({
          text: "Sample Text"
        });
        console.log(textSym, markerSymbol);
        var pointGraphic = new Graphic({
          geometry: point,
          symbol: markerSymbol,
          popupTemplate: popupTemplate
        });
        var a = new MapView(mapViewProperties);

        a.graphics.add(pointGraphic);

验证定义中模块的顺序,它必须与函数参数的顺序完全匹配。