[LayaAir 2.0]tiledMap问题,getTileProperties获取地图属性不能获取到

IDE:2.0.0bate5.1
tiled版本:2019.02.10
调用getTileProperties返回结果一直为null，看了源码发现不管传入什么参数都会返回为null。
因为_tileProperties初始化的完成后就为{0:undefined}。
 
 
/**
    *得到tile自定义属性
    *@param index 地图块索引
    *@param id 具体的TileSetID
    *@param name 属性名称
    *@return
    */
    __proto.getTileProperties=function(index,id,name){
        if (this._tileProperties[index] && this._tileProperties[index][id]){
            return this._tileProperties[index][id][name];
        }
        return null;
    }
 
 
import { ui } from '../ui/layaMaxUI';
/**主界面 */
export default class Main extends ui.mainUI {
/**地图链接 */
MAP_URL:string = 'res/tiled/map.json'; 
/**地图 */
map: Laya.TiledMap;
constructor(){
super();
Laya.loader.create(this.MAP_URL, new Laya.Handler(this, this.onComplete))
} 
private onComplete(){
this.map = new Laya.TiledMap();
this.map.createMap(this.MAP_URL, new Laya.Rectangle(0,0,Laya.stage.width, Laya.stage.height), new Laya.Handler(this, this.onMap))
} 
private onMap(){
var idx = this.map.getLayerByIndex(0).getTileDataByScreenPos(20,20);
var pass = this.map.getTileProperties(0,idx - 1,'pass');
console.log('打印=======================================')
console.log(idx, pass, this.map['_tileProperties'],this.map['_tileProperties2']);
// 30 null {0:undefined} {}
}
}求官方给个回复