[]请教Laya.BitmapFont加载位图文字不能显示的问题

// 程序入口

class GameMain{

    private mFontName:string = "diyFont";

    private mBitmapFont:Laya.BitmapFont;



    constructor()

    {

        Laya.init(600,400);

        this.mBitmapFont = new Laya.BitmapFont();

        this.mBitmapFont.loadFont("../laya/assets/txt.fnt", new Laya.Handler(this.onLoaded));

    }



    private onLoaded():void

    {

        this.init();

    }



    private init():void

    {

        this.mBitmapFont.setSpaceWidth(10);

        Laya.Text.registerBitmapFont(this.mFontName, this.mBitmapFont);



        var txt:Laya.Text = new Laya.Text();

        txt.text = "武器坐骑角色";

        txt.width = 250;

        txt.height = 250;

        txt.wordWrap = true;

         txt.align = "center";

        txt.font = this.mFontName;

        txt.fontSize = 50;

        txt.leading = 5;

        Laya.stage.addChild(txt);

    }

}

new GameMain();

资源能加载到，但运行后什么都没有看见。请问谁知道为啥？