MapContext.setLocMarkerIcon(Object object)怎么用？

this.mapCtx = wx.createMapContext('myMap')

    this.mapCtx.moveToLocation();

    this.mapCtx.setLocMarkerIcon({

      iconPath:"https://res.wx.qq.com/wxdoc/dist/assets/img/map.dd86f5e2.jpg",

   complete:function(res){

        console.log('setLocMarkerIcon')

        console.log(res)

      }

    })

用了，图片没有改成功