//几何对象不一定要叠加,可以根据几何对象确定信息显示的位置
var CurPos = new Point(CurX, CurY, map.spatialReference);
map.infoWindow.setContent("长度:" + caculateResult); //显示的内容
map.infoWindow.show(CurPos); //显示的位置
//确定中心点
var CurX = (currentGrahpic.cache._extent.xmax +currentGrahpic.cache._extent.xmin) / 2;
var CurY = (currentGrahpic.cache._extent.ymax+currentGrahpic.cache._extent.ymin) / 2;
var CurPos = new Point(CurX, CurY, map.spatialReference);