map拖动后的经纬度怎么获取？

getCenterLocation: function (e) {
    let that = this
    if (e.type == 'end' && e.causedBy == 'drag') {
      that.mapCtx.getCenterLocation({
        success(res) {
          that.setData({
            lat: res.latitude,
            lng: res.longitude
          })
          //that.moveGetUsers()
        }
      })
    }
  },