Question

`我的＆＃34;型号＆＃34;是一个扩展EventDispatcher的AS类：

MeetingInfoModel extends EventDispatcher

在本课程中，我播放了一个自定义事件：

var eventObj:CustomEvent = new CustomEvent( CustomEvent.UPDATE_DOC_COUNTER );
        dispatchEvent( eventObj );

我在课程顶部包含元数据标签：

[Event(name="updateDocCounter", type="com.fmr.transporter.events.CustomEvent")]

我尝试在MXML组件中侦听此事件：

this.addEventListener( CustomEvent.UPDATE_DOC_COUNTER, onDocUpdate );

但它永远不会到达这个听众。

我经常遇到这样的问题，我认为事件过程的关键部分是我不理解的。

有人能提供任何有用的线索吗？

谢谢！

更新：

回应以下所有评论（感谢所有回复！）：

MeetingInfoModel不是显示组件，不应负责广播事件;这是我没有得到的那件!!

这是我的代码：在MeetingInfoModel构造函数中，我监听其某个类成员的集合更改事件：

docsAndAttachmentsList.addEventListener( CollectionEvent.COLLECTION_CHANGE, updateDocsCounter );

在那个处理程序中，我尝试广播一个MXML组件（它是显示层次结构的一部分）将处理的事件：

private function updateDocsCounter( event:CollectionEvent ):void
    {           
        var eventObj:CustomEvent = new CustomEvent( CustomEvent.UPDATE_DOC_COUNTER );
        dispatchEvent( eventObj );
    }

回到MXML组件，我从creationComplete处理程序调用此方法：

private function addListeners():void{
            MeetingInfoModel.getInstance().addEventListener( CustomEvent.UPDATE_DOC_COUNTER, onDocUpdate );
        }

听起来我应该只听MXML组件上的集合更改事件。我试过了，但它不起作用：

MeetingInfo.getInstance().docsAndAttachmentsList.addEventListener( CollectionEvent.COLLECTION_CHANGE, updateDocsCounter );

我不知道为什么不工作;它似乎是最好的解决方案。

这是完整的MeetingInfoModel类：

[Bindable]
[Event(name="updateDocCounter", type="com.fmr.transporter.events.CustomEvent")]
public final class MeetingInfoModel extends EventDispatcher
{
    //Universal INFO
    public var generalInfo:GeneralInfoModel;
    public var meetingVO:MeetingVO = new MeetingVO();
    public var meetingId:String;

    public var bulletinBoardLiveMembers:ArrayCollection = new ArrayCollection();

    public var xmppServices:XMPPServices;

    public var declinedParticipantsGroup:ArrayCollection = new ArrayCollection();
    public var notJoinedParticipantsGroup:ArrayCollection = new ArrayCollection();
    public var conferenceRoomParticipantsGroup:ArrayCollection = new ArrayCollection();
    public var otherLocationParticipantsGroup:ArrayCollection = new ArrayCollection();

    [Bindable]
    public var documentList:ArrayCollection = new ArrayCollection();

    [BIndable]
    public var newAttachmentList:ArrayCollection = new ArrayCollection();
    public var docsAndAttachmentsList:ArrayCollection = new ArrayCollection();

    public var bulletinBoardMsgList:ArrayCollection = new ArrayCollection();

    private var _participantList:ArrayCollection = new ArrayCollection();
    public var dismissedMeetingIDs:Array = [];
    public var visibleToastWindows:Array = [];

    public function MeetingInfoModel()
    {
        generalInfo = GeneralInfoModel.getInstance();
        xmppServices = XMPPServices.getInstance();
        _participantList.addEventListener(CollectionEvent.COLLECTION_CHANGE, allParticipantsChangeHandler);
        bulletinBoardLiveMembers.addEventListener(CollectionEvent.COLLECTION_CHANGE, bulletinBoardLiveMembersChangeHandler);
        docsAndAttachmentsList.addEventListener( CollectionEvent.COLLECTION_CHANGE, updateDocsCounter );
    }

    private static var model:MeetingInfoModel = null;

    public static function getInstance():MeetingInfoModel
    {
        if (model == null)
        {
            model = new MeetingInfoModel();
        }
        return model;
    }

    /** 
     * The handler for the collection change event of the docsAndAttachmentsList collection. 
     * 
     * We use it to manually update the counter on the Docs tab.
     */
    private function updateDocsCounter( event:CollectionEvent ):void
    {           
        var eventObj:CustomEvent = new CustomEvent( CustomEvent.UPDATE_DOC_COUNTER );
        dispatchEvent( eventObj );
    }

    public function displayToastForThisMeeting(meetingID:Number):Boolean
    {
        //trace("model::meetingID = " + meetingID);
        var doDisplayToast:Boolean = false;
        var containsMeetingID:Boolean = false;
        //the first one
        if(dismissedMeetingIDs.length == 0)
        {
            //trace("dismissedMeetingIDs.length = 0");
            doDisplayToast = true;
            dismissedMeetingIDs.push(meetingID);
        }
        else
        {
            for(var i:int=0; i < dismissedMeetingIDs.length; i++)
            {
                //trace("dismissedMeetingIDs[" + i + "] = " + dismissedMeetingIDs[i]);
                if(meetingID == dismissedMeetingIDs[i])
                {   //this one has already been dismissed
                    doDisplayToast = false;
                    containsMeetingID = true;
                    break;
                }
                else
                {
                    doDisplayToast = true;
                    containsMeetingID = false;
                }
            }

            if(containsMeetingID == false)
            {
                dismissedMeetingIDs.push(meetingID);
            }
        }
        return doDisplayToast;
    }

}

这是我的MXML组件中的一些代码（其基类是Group）：

import com.fmr.transporter.controller.TransporterController;
        import com.fmr.transporter.events.CustomEvent;
        import com.fmr.transporter.model.MeetingInfoModel;
        import com.fmr.transporter.model.TransporterModel;

        import mx.collections.ArrayCollection;
        import mx.core.FlexGlobals;
        import mx.events.CollectionEvent;
        import mx.events.FlexEvent;

        private var controller:TransporterController;

        [Bindable] public var newAttachmentsList:ArrayCollection;

        [Bindable] public var meetingInfo:MeetingInfoModel;

        private function complete():void
        {
            controller = TransporterController.getInstance();

            addListeners();
        }

        /** Add listeners to this class.
         */
        private function addListeners():void{
            MeetingInfo.getInstance().docsAndAttachmentsList.addEventListener( CollectionEvent.COLLECTION_CHANGE, updateDocsCounter );
        }

Answer 1

您扩展了活动类。默认情况下，flex事件不会冒泡。您需要将CustomEvent类构造函数修改为如下所示：

public function CustomEvent(type:String){
    super(type, true, true);
}

这将使您的事件冒泡并且每个flex事件框架也可取消。 @The_asMan正确告诉你如何处理非冒泡事件，但我想你可能不小心错过了正确的对象。让它泡泡，你会听到!!

Answer 2

@LondonDrugs_MediaServices，@ Flextras和@The_asMan。

这些家伙是对的;似乎该类不必在显示列表上以便监听事件。只要你有一个调度事件的类的正确目标，它应该没问题。

出于某种原因，我做了一些非常奇怪的事情，最终无法弄明白。解决方案是对我在模型中更新的集合使用绑定，以便更新我想要的组件。

感谢大家的非常有益的评论。

从模型广播自定义事件

2 个答案: