[]获取的ui页面里下on事件无法触发

类代码如下：
var GameStartView = function () {
GameStartView.super(this);
this.Start.on(Laya.Event.CLICK, this, this.open);
console.log(this.Start);
GameStartView.prototype.open = function(){
console.log("Open is ok");
}
};
Laya.class(GameStartView,"GameStartView", GameStartUI);
输出：Button {toggle: false, _bitmap: AutoBitmap, _text: Text, _strokeColors: null, _state: 0…}
其中为什么on事件无法触发，该怎么样写？谢谢！