Question

我有两个名为Guest和Guest2的类。我想知道是否可以从Guest2类中删除Guest类中的eventlistener。以下是完整的代码。注意：两个类都具有完全相同的代码

package 
        {
    import flash.display.MovieClip;
        import flash.events.Event;
        import flash.events.MouseEvent;
        import flash.filters.*;

        public class Guest extends MovieClip
        {
            var walkSpeed:Number = 5;
            var oldPosX;
            var oldPosY;

            var myGlow:GlowFilter = new GlowFilter();

            public function Guest()
            {   
                addEventListener(MouseEvent.MOUSE_OVER, addGlow);
            }

            function addGlow(event:MouseEvent):void
            {
                filters = [myGlow];
                addEventListener(MouseEvent.MOUSE_OUT, removeGlow);
                addEventListener(MouseEvent.CLICK, ready);

            }

            function removeGlow(event:MouseEvent):void
            {
                filters = [];
            }

            function ready(event:MouseEvent):void
            {
                filters = [myGlow];
                stage.addEventListener(MouseEvent.MOUSE_DOWN, walk);
                removeEventListener(MouseEvent.MOUSE_OUT, removeGlow);
                **MovieClip(root).Guest02.addEventListener(MouseEvent.CLICK, walkTo);**
            }

            function walk(event:MouseEvent):void
            {
                oldPosX = parent.mouseX;
                oldPosY = parent.mouseY;
                rotation = Math.atan2(oldPosY - y,oldPosX - x) / Math.PI * 180;
                filters = [];
                stage.removeEventListener(MouseEvent.MOUSE_DOWN, walk);
                stage.addEventListener(Event.ENTER_FRAME, loop);
            }

            function loop(event:Event):void
            {
                var dx:Number = oldPosX - x;
                var dy:Number = oldPosY - y;
                var distance:Number = Math.sqrt((dx*dx)+(dy*dy));
                if (distance<walkSpeed)
                {
                    // if you are near the target, snap to it
                    x = oldPosX;
                    y = oldPosY;
                    removeEventListener(Event.ENTER_FRAME, loop);

                }
                else
                {
                    x = x+Math.cos(rotation/180*Math.PI)*walkSpeed;
                    y = y+Math.sin(rotation/180*Math.PI)*walkSpeed;
                }

            }

            **function walkTo(event:MouseEvent):void
            {
                _Guest02.removeEventListener(MouseEvent.CLICK, ready);
            }**

        }
    }

Answer 1

正如Jake King已经指出的那样，您可能希望在面向对象编程方面重新审视您的代码。如果你说两个类共享完全相同的功能，为什么不设置一个类Guest并创建两个实例，例如guest1和guest2。

关于事件处理程序的问题，您需要将侦听器存储在一个公共实例变量中，然后可以从另一个实例（坏样式）访问，或者编写一个允许删除的专用公共函数监听器变量保持私有状态：

public class Guest extends MovieClip
{
    private var overListener;

    public function Guest()
    {   
        overListener = addEventListener(MouseEvent.MOUSE_OVER, addGlow);
    }

    public function removeOverListener() 
    {
        if (overListener) {
            removeEventListener(MouseEvent.MOUSE_OVER, overListener);
        }
    }

    ...
}

如果guest1和guest2都是Guest的实例，并且guest1引用了guest2的guest2，那么您可以从guest1中删除guest2中的侦听器，如下所示：

guest2.removeOverListener();

如何从一个类访问事件处理程序到另一个类（第2部分）as3

1 个答案: