为什么删除事件侦听器不起作用? [英] Why doesn't removing event listeners work?

问题描述

我的构造函数中有这个:

I have this in my constructor:

addEventListener(Event.REMOVED_FROM_STAGE, actualDestroy);

这在实际销毁中:

    public function actualDestroy(e:* = null){
        removeEventListener(Event.REMOVED_FROM_STAGE,actualDestroy);
        if(this.parent){
            this.parent.removeChild(this);
        }
    }

问题是我收到错误:错误 #2094:事件调度递归溢出.如果 this.parent 不存在，为什么 removechild 不断被调用?为什么删除事件侦听器不起作用?

The problem is I get Error: Error #2094: Event dispatch recursion overflow. Why does removechild keep getting called if this.parent does not exist? Why doesn't removing event listeners work?

推荐答案

事件名称具有误导性.removedFromStage，根据文档，在显示对象即将从显示列表中删除时分派".换句话说，这就是您的代码中发生的事情:

The name of the event is misleading. removedFromStage, according to the docs, is "dispatched when a display object is about to be removed from the display list". In other words, this is what's happening in your code:

1. 在代码中的某处调用 parent.removeChild(this)
2. actualDestroy 立即被调用.此时对象还在显示列表中，所以this.parent != null
3. 在 actualDestroy 中，您再次调用 parent.removeChild(this).
4. 转到第 2 步

1. Somewhere in your code, you call parent.removeChild(this)
2. actualDestroy is immediately called. At this point, the object is still in the display list, so this.parent != null
3. In actualDestroy, you call parent.removeChild(this) again.
4. Go to step 2

所以为了解决这个问题，你可能想要重构你的代码(一个对象从显示列表中删除自己从来都不是一个好主意)，或者使用一些像 beingRemoved 这样的布尔值来检查是否该对象已从列表中删除.在这种情况下，不要在 actualDestroy 中调用 parent.removeChild(this).

So to fix the issue, you might want to refactor your code (an object removing itself from the display list is never a good idea anyway), or perhaps use some boolean like beingRemoved to check whether the object is being removed from the list already. In which case, don't call parent.removeChild(this) in actualDestroy.

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