Actionscript 3 没有键盘输入AS3

所以我试图从用户那里获得键盘输入来移动一个字符。它在我使用的另一个程序中工作，我复制粘贴，但在这个程序中不工作。它给了我

第87行第38列1119：通过静态类型类的引用访问可能未定义的属性EVENT\u FRAME。

我似乎不知道问题出在哪里

这是我按下开始按钮时使用的按钮单击功能

    public function buttonClick(ev:MouseEvent):void
    {
        createGameScreen();
        this.mcLink.gotoAndPlay("Idle");
        this.mcLink.x=50;
        this.mcLink.y=200;
        this.mcLink.scaleX=this.mcLink.scaleY=3;
        this.stage.addEventListener(Event.EVENT_FRAME, this.enterFrameHandler, false, 0, true);
    }

这是键盘输入的事件处理程序函数

public function enterFrameHandler($e:Event):void
    {
        if (this.mcLink)
        {               
            if (KeyboardManager.instance.isKeyDown(KeyCode.DOWN))
            {
                if (this.mcLink.y + this.mcLink.height > this.stage.stageHeight || this.mcLink.y - this.mcLink.height <= 0)
                {
                    this.mcLink.y += -15;
                    mcLink.gotoAndPlay("Idle");
                    return;
                }
                this.mcLink.y += _nHeroMovementSpeed;
                mcLink.gotoAndPlay("Down");
            }
            else if (KeyboardManager.instance.isKeyDown(KeyCode.UP))
            {
                if (this.mcLink.y + this.mcLink.height > this.stage.stageHeight || this.mcLink.y - this.mcLink.height <= 0)
                {
                    this.mcLink.y += 15;
                    mcLink.gotoAndPlay("Idle");
                    return;
                }
                this.mcLink.y -= _nHeroMovementSpeed;
                mcLink.gotoAndPlay("Up");
            }

            if (KeyboardManager.instance.isKeyDown(KeyCode.LEFT))
            {
                if (this.mcLink.x + this.mcLink.width > this.stage.stageWidth || this.mcLink.x - this.mcLink.width <= 0) 
                {
                    this.mcLink.x += 15;
                    mcLink.gotoAndPlay("Idle");
                    return;
                }                   
                this.mcLink.x -= _nHeroMovementSpeed;
                mcLink.gotoAndPlay("Left");

            }
            else if (KeyboardManager.instance.isKeyDown(KeyCode.RIGHT))
            {   
                if (this.mcLink.x + this.mcLink.width > this.stage.stageWidth || this.mcLink.x - this.mcLink.width <= 0) 
                {
                    this.mcLink.x += -15;
                    mcLink.gotoAndPlay("Idle");
                    return;
                }
                this.mcLink.x += _nHeroMovementSpeed;
                mcLink.gotoAndPlay("Right");
            }
        }
    }

公共函数enterFrameHandler（$e:Event）：无效
{
if（this.mcLink）
{               
if（KeyboardManager.instance.isKeyDown（KeyCode.DOWN））
{
如果（this.mcLink.y+this.mcLink.height>this.stage.stageHeight | this.mcLink.y-this.mcLink.height this.stage.stageHeight | this.mcLink.height this.stage.stageWidth | this.mcLink.x-this.mcLink.width | this.stage.mcLink.x-this.mcLink.width你的意思是什么

这一行代码在另一个程序中运行，这与我现在的工作几乎相同。我不确定它是否在我们老师提供的包中
this.stage.addEventListener(Event.ENTER_FRAME, this.enterFrameHandler, false, 0, true);
//                                ^^^^^^^^^^^ EVENT_FRAME isn't a known Event.