在egret中的TS类的深拷贝

public static copyThisOfSonClass(item: ItemInfo): ItemInfo {
        let construClassName = egret.getQualifiedClassName(item);
        let obj = new window[construClassName];

        for (var key in item) {
            if (item.hasOwnProperty(key)) {
                if (key == "__class__" || key == "__types__") continue;
                var element = item[key];
                obj[key] = element;
            }
        }

        return obj;
}