actionscript-3 - 将其设为外部后的类错误

Question

我在我的舞台上有对象 char，我用 main.as 控制它，但是当我决定把它做成 char.as 并将它添加到 main.as 时，就变成了错误..

主文件

package 
{

    import flash.display.MovieClip;
    import flash.events.*;
    import flash.display.Sprite;
    import flash.sampler.DeleteObjectSample;
    import flashx.textLayout.utils.CharacterUtil;


    public class main extends MovieClip
    {

        public function main()
        {
            var mychar:char = new char();
            mychar.x = 60;
            mychar.y = 60;
            addChild(mychar);
        }

    }
}

字符.as

package 
{

    import flash.display.MovieClip;
    import flash.events.*;
    import flash.display.Sprite;
    import flash.sampler.DeleteObjectSample;


    public class char extends MovieClip
    {
        //char vars
        var isRight:Boolean = false;
        var isLeft:Boolean = false;
        var isUp:Boolean = false;
        var isDown:Boolean = false;
        var angleDegree;
        var angleRadian;
        //stage vars
        var objects = new Array(50);


        public function char()
        {
            for (var i = 0; i<numChildren; i++) {
                objects[i] = getChildAt(i);
            }

            addEventListener(Event.ENTER_FRAME, charEnterFrame);
            addEventListener( MouseEvent.MOUSE_DOWN , MouseClick);
            addEventListener(KeyboardEvent.KEY_DOWN, KeyDown);
            addEventListener(KeyboardEvent.KEY_UP, KeyUp);
        }
        function charEnterFrame(e:Event)
        {

            // **Char rotation
            angleRadian=Math.atan2(mouseY-this.y,mouseX-this.x);
            angleDegree = angleRadian * 180 / Math.PI;
            this.rotation = angleDegree;
            // **Char Movement
            if (isRight==true)this.x +=  5;
            if (isLeft==true)this.x -=  5;
            if (isUp==true)this.y -=  5;
            if (isDown==true)this.y +=  5;



        }
        function MouseClick(event:MouseEvent)
        {
            var radius = 30;
            trace(objects.length);
            var dx = radius * Math.cos(angleRadian);
            var dy = radius * Math.sin(angleRadian);
            var movex = 20 * Math.cos(angleRadian);
            var movey = 20 * Math.sin(angleRadian);
            var bullet = new Sprite();
            bullet.graphics.beginFill(0x000000);
            bullet.graphics.drawCircle(this.x+dx, this.y+dy, 3);
            bullet.graphics.endFill();
            var i = 1;
            var f:Function;
            addChild(bullet);
            bullet.addEventListener(Event.ENTER_FRAME, f = function(){ 
            bullet.x += movex*i;
            bullet.y += movey*i;
            for (var j = 0; j < objects.length-1; j++) {
                if (bullet.hitTestObject(objects[j])) {
                    bullet.graphics.clear();
                }
            }
            i++;
            });

        }

        function KeyDown(event:KeyboardEvent):void
        {
            if (event.keyCode == 39)isRight = true;
            if (event.keyCode == 37)isLeft = true;
            if (event.keyCode == 38)isUp = true;
            if (event.keyCode == 40)isDown = true;
        }
        function KeyUp(event:KeyboardEvent):void
        {
            if (event.keyCode == 39)isRight = false;
            if (event.keyCode == 37)isLeft = false;
            if (event.keyCode == 38)isUp = false;
            if (event.keyCode == 40)isDown = false;

        }

    }
}

闪现结果：http://www.shareswf.com/media/games/swf/28063.swf