Flex中通过监听ObjectProxy的propertyChange事件检测一个Object是否变化的例子_object proxy代理判断一个对象有没有变化-优快云博客

本文介绍了使用Adobe Flex框架进行事件监听及属性变更处理的方法。通过ObjectProxy类可以方便地为对象添加事件监听器，当对象属性发生变化时，能够触发相应的事件处理函数，实现对属性变化的实时响应。

<?xml version="1.0" encoding="utf-8"?>
<mx:Application xmlns:mx="http://www.adobe.com/2006/mxml"
        layout="vertical"
        verticalAlign="middle"
        backgroundColor="white"
        creationComplete="init();" viewSourceURL="srcview/index.html">

    <mx:Script>
        <![CDATA[
            import mx.events.PropertyChangeEvent;
            import mx.utils.ObjectProxy;

            private var object:Object = {};
            private var objectProxy:ObjectProxy;

            private function init():void {
                objectProxy = new ObjectProxy(object);
                objectProxy.addEventListener(PropertyChangeEvent.PROPERTY_CHANGE, updateChange);
                objectProxy.name = "My Object";
                objectProxy.id = 31;

                /* Note: Any assignments made directly to the "object"
                   Object do not dispatch the propertyChange event. */
                object.isDebug = false;
                object.id = 33;

                /* Note: Even though the earlier assignment to the "id"
                   property  didn't dispatch the propertyChange event,
                   the "oldValue" property is still displayed as 33. */
                objectProxy.id = 45;
            }

            private function updateChange(evt:PropertyChangeEvent):void {
                arrColl.addItem(evt);
            }
        ]]>
    </mx:Script>

    <mx:ArrayCollection id="arrColl" />

    <mx:DataGrid dataProvider="{arrColl}"
            sortableColumns="false"
            draggableColumns="false"
            width="100%"
            height="100%">
        <mx:columns>
            <mx:DataGridColumn dataField="type" />
            <mx:DataGridColumn dataField="property" />
            <mx:DataGridColumn dataField="newValue" />
            <mx:DataGridColumn dataField="oldValue" />
            <mx:DataGridColumn dataField="source" />
        </mx:columns>
    </mx:DataGrid>

</mx:Application>