arcgis api for js 4.x学习笔记（2）绘制面(Draw)及面积计算(geodesicArea)
<button id="btnDrawPolygon">面</button><button id="clearPolygon">清除</button>//本文对应Api 4.6版本 require([ 'dojo/on', 'dojo/dom', 'esri/views/2d/draw/Draw',
