这是我的启动类

// 程序入口
class GameMain {


    constructor() {
        Laya.init(600, 400);
        Laya.stage.bgColor = "#123456";
        Laya.loader.load([
            { url: "res/beijing/beijing2.png", type: Laya.Loader.IMAGE },
            { url: "res/atlas/comp.png", type: Laya.Loader.IMAGE },
            { url: "res/atlas/comp.atlas", type: Laya.Loader.ATLAS }],
            Laya.Handler.create(this, this.onLoaded), Laya.Handler.create(this, this.onLoading));
    }

    static aaa(): void {

    }

    private onLoaded(): void {
        var info = new view.GameInfo();
        info.zOrder = 99;//置最顶,这句话不写图层看不见
        // info.init();
        Laya.stage.addChild(info);
    }

    private onLoading(): void {
        var bj = new BeiJing();
        Laya.stage.addChild(bj);
    }

}
new GameMain();

这个是我的UI类，我在这个类里调用GameMain.aaa();提示TypeError: GameMain.aaa is not a function
问题是我调用其他类的静态函数就没问题，请问这是什么？

/**Created by the LayaAirIDE*/
module view {
	export class GameInfo extends ui.GameInfoUI {
		constructor() {
			super();
			this.kaishi_btn.on(Laya.Event.MOUSE_DOWN, this, this.onStart);
			// Laya.stage.on(Laya.Event.MOUSE_DOWN, this, this.birdFly);//可以绑定两个函数
			Laya.stage.on(Laya.Event.KEY_DOWN, this, this.birdFly);
			this.init();
		}
		public init(): void {
			Laya.Tween.to(this.kaishi_btn, { y: 200 }, 800, Laya.Ease.backOut, Laya.Handler.create(this, this.onLogoCompete));
		}

		onLogoCompete(): void {
			Laya.Tween.to(this.biaoti_lable, { y: 120 }, 800, Laya.Ease.backOut);
		}

		onStart(): void {
			Laya.Tween.to(this.kaishi_btn, { y: 400 }, 800, Laya.Ease.backIn, Laya.Handler.create(this, this.onLogoStart));
		}

		onLogoStart(): void {
			Laya.Tween.to(this.biaoti_lable, { y: -40 }, 800, Laya.Ease.backIn, Laya.Handler.create(this, this.startGame));
		}

		birdFly(): void {
			console.log("我飞!");
		}

		startGame(): void {
			console.log("开始游戏!");
			GameMain.aaa();
		}
	}
}