AS3不能从自定义类访问舞台 [英] AS3 Cannot access stage from custom class

问题描述

我如何可以访问阶段，尤其是Flash影片的宽度和鼠标的位置从自定义类？

How can I access the stage and especially the width and mouse position of the flash Movie from a custom class?

package classes
{
   import flash.events.*;
   import flash.display.*;

   public class TableManager extends Sprite
   {
        public function TableManager() {
            sayStage();
        }
        public function sayStage():void 
        {
            trace(stage);
        }
  }   
} 

这将只返回nill。我知道的DisplayObject没有任何阶段，直到他们已经启动，所以你不能访问舞台在构造函数，但即使我打电话sayStage（）以后作为一个实例方法是行不通的。

This will only return nill. I know that DisplayObjects don't have any stage until they have been initiated so you can't access the stage in your constructor but even if I call sayStage() later as an instance method it won't work.

我是什么做错了吗？

推荐答案

如果TableManager是在舞台上，你可以访问舞台与 this.stage 。

If TableManager is on the stage you can access the stage with this.stage.

诀窍是，你必须等待实例被添加到舞台上。你可以听的 ADDED_TO_STAGE 事件，所以你知道什么时候发生的事情。

The trick is you have to wait for the instance to be added to the stage. You can listen for the ADDED_TO_STAGE event so you know when that's happened.

package classes {
import flash.events.*;
import flash.display.*;

public class TableManager extends Sprite {
    public function TableManager() {
        this.addEventListener(Event.ADDED_TO_STAGE, onAddedToStage);
    }

    private function onAddedToStage(e:Event):void {
        this.removeEventListener(Event.ADDED_TO_STAGE, onAddedToStage);
        sayStage();
    }

    public function sayStage():void {
        trace(this.stage);
    }
}   
}

这篇关于AS3不能从自定义类访问舞台的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！