actionscript-3 – Flash：使用一个eventlistener监听一个类型的所有事件

这不是生死攸关的问题,但我想知道这是否可行：

我从一种类型的自定义事件(FormEvent)中获得了一些事件,现在我得到了一个Formlistener,它监听所有这些事件并根据事件类型处理它们.我希望一次添加所有事件,而不是添加一个eventListener.

所以现在它看起来像这样：

private function addListeners():void {

        addEventListener(FormEvent.SHOW_FORM,formlistener);
        addEventListener(FormEvent.SEND_FORM,formlistener);
        addEventListener(FormEvent.CANCEL_FORM,formlistener);
    }



        private function formlistener(event:formEvent):void {

        switch(event.type){
            case "show.form": 
                // handle show form stuff
            break;
            case "send.form":
                // handle send form stuff
            break;
            case "cancel.form":
                // handle cancel form stuff
            break;
        }
    }

但是,我宁愿做类似的事情,而不是每次添加一个事件

private function addListeners():void {

        addEventListener(FormEvent.*,formlistener);
    }

我想知道这样的事情是否可行,我会喜欢它.我处理大量事件:)

解决方法

无论如何,在这种情况下你只需要一个事件监听器.该监听器将使用表单和一个参数来监听任何更改,该参数等于事件监听器函数可用的更改.我会告诉你,但请记住这是一个伪情况,通常我不会发送一个像方法调用这样简单的事件,因为调度是隐含的,所以没有真正需要监听它.

首先是自定义事件

package com.yourDomain.events
{
    import flash.events.Event;
    public class FormEvent extends Event
    {
        //Public Properties
        public static const CANCEL_FORM:int = "0";
        public static const SHOW_FORM:int = "1";
        public static const SEND_FORM:int = "2";

        public static const STATE_CHANGED:String = "stateChanged";

        //Private Properties
        private var formState:int;

        public function FormEvent(formState:int):void
        {
            super(STATE_CHANGED);
            formState = formState;
        }
    }
}

所以我们刚刚创建了我们的自定义事件类,我们已经设置好了,以便我们可以通过监听器函数捕获状态,因为我将演示一旦使用将为所述自定义事件调度的伪表单类.

请记住,这都是假设,因为我不知道您的代码是什么样的或者您的实现方式.重要的是要注意,当我发送事件时,我需要发送一个反映新状态的参数.

package com.yourDomain.ui
{
   import flash.events.Event;
   import flash.events.Eventdispatcher;
   import com.yourDomain.events.FormEvent;
   public class Form extends Eventdispatcher
   {
     public function Form():void
     {
        //Anything you want form to do upon instantiation goes here.
     }
     public function cancelForm():void
     {
        dispatchEvent(new Event(FormEvent.CANCEL_FORM);
     }
     public function showForm():void
     {
        dispatchEvent(new Event(FormEvent.SHOW_FORM);
     }
     public function sendForm():void
     {
        dispatchEvent(new Event(FormEvent.SEND_FORM);
     }
   }
}

最后,我们创建了将要监听它的文档类.请注意,我知道创建一个在调用类的方法时触发的侦听器是不合逻辑的,因为您显然知道您调用了该方法,但是对于此示例,它将到期.

package com.yourDomain.ui
{
   import com.yourDomain.ui.Form;
   import com.yourDomain.events.FormEvent;
   //Form is in the same package so we need not import it.
   public class MainDocumentClass
   {
      private var _theForm:Form;

      public function MainDocumentClass():void
      {
         _theForm  = new Form();
         _theForm.addEventListener(FormEvent.STATE_CHANGED,onFormStateChange,false,true);
         /*
         The following three method calls each cause the
         FormEvent.STATE_CHANGE event to be dispatched.  
         onFormStateChange is notified and checks what 
         the last change actually was.
         */
         _theForm.cancelForm();
         _theForm.showForm();
         _theForm.sendForm();
      }
      private function onFormStateChange(e:FormEvent):void
      {
         switch(e.formState)
         {
            case CANCEL_FORM:
              trace('The form was canceled');
              break;
            case SHOW_FORM:
              trace('The form was revealed');
              break;
            case SEND_FORM:
              trace('The form was sent');
              break;
         }
      }
   }      
}

我希望这很有用,它很晚,我可能不得不稍后修改一些东西,但这应该有助于理解如何制作自己的事件并定制工作方式.