ActionScript：如何检查一个偶数以完成？

我从来没有写过动作脚本。需要听众的帮助。我正在调用和event DrawManager.ZOOM_TO_SELECTION，但需要等待此事件完成，然后才能调用下一个函数“saveMapImage”。有人能告诉我如何用代码示例来实现这一点吗

    public function saveMapImageAndForward(projectLocationWKT:String, projectMapType:String, hasMapImageFromIPaCMap:String, projectName:String):void {
        this.projectLocationWKT = projectLocationWKT;
        this.projectMapType = projectMapType;
        this.hasMapImageFromIPaCMap = hasMapImageFromIPaCMap;
        this.projectName = projectName;

        //GlobalDispatcher.dispatchEvent(new Event(Event.COMPLETE));

         GlobalDispatcher.dispatchEvent(new AppEvent(DrawManager.ZOOM_TO_SELECTION));

        //GlobalDispatcher.removeEventListener

        saveMapImage();
    }

提前谢谢

public function someFunctionCalledAheadOfTime():void
{
    .
    .
    .
    GlobalDispatcher.addEventListener(DrawManager.ZOOM_TO_SELECTION, saveMapImage);
    .
    .
    .
}

public function saveMapImageAndForward(projectLocationWKT:String, projectMapType:String, hasMapImageFromIPaCMap:String, projectName:String):void {
    this.projectLocationWKT = projectLocationWKT;
    this.projectMapType = projectMapType;
    this.hasMapImageFromIPaCMap = hasMapImageFromIPaCMap;
    this.projectName = projectName;

    //GlobalDispatcher.dispatchEvent(new Event(Event.COMPLETE));

     GlobalDispatcher.dispatchEvent(new AppEvent(DrawManager.ZOOM_TO_SELECTION));

    //GlobalDispatcher.removeEventListener

    //saveMapImage();
}

private function saveMapImage(pEvent:AppEvent):void
{
    .
    .
    .
}

---

编辑：看起来AppEvent不是一个非常标准的类，它可能是您自己的类。我是基于AppEvent继承自Event的假设，并且单参数构造函数的工作方式与常规事件相同。

另一种方法是使用ZoomEvent.ZOOM\u END。但是，如果地图已经放大，此事件将永远不会触发。如果您的程序正在侦听事件ZoomEvent.ZOOM\u END.，则可能需要添加计时器以重定向到备用路径。