事件处理2

<?xml version="1.0" encoding="utf-8"?>
<mx:Application xmlns:mx="http://www.adobe.com/2006/mxml" layout="absolute" creationComplete="initApp()">
    <mx:Script>
        <![CDATA[
            import flash.events.MouseEvent;
            internal function initApp():void{
                canvas1.addEventListener(MouseEvent.CLICK,CanvasHandler);
                canvas2.addEventListener(MouseEvent.CLICK,CanvasHandler);
                btn1.addEventListener(MouseEvent.CLICK,pressBtn);   //因为都没有打开捕获功能，所以输出时从下往上。
                btn2.addEventListener(MouseEvent.CLICK,pressBtn,true);  
                //btn2打开了事件捕获功能,所以输出时从上向下，又因为CanvasHandler函数中有stopImmediatePropagation(),所以到这执行不下去。
            }
            internal function output(msg:String):void{
                txtArea1.text += msg+" ";
            }
            internal function pressBtn(event:MouseEvent):void{
                this.output("是否冒泡---"+event.bubbles);//event.bubbles 表示是否打开冒泡功能
                //输出当前的点击对象和事件流当前的阶段，1表示捕获阶段，2表示目标阶段，3表示冒泡阶段
                this.output("目标对象："+event.target+":"+event.eventPhase);
                //输出当前正在处理的对象
                this.output("遍历对象："+event.currentTarget);
                this.output("------------");
            }
            internal function CanvasHandler(event:MouseEvent):void{
                output("目标对象---"+event.target+"----"+event.eventPhase);
                event.stopImmediatePropagation();  //停止事件流的传播
            }
        ]]>
    </mx:Script>
    <mx:Canvas x="10" y="10" width="328" height="355" id="canvas1">
        <mx:Text x="21" y="10" text="canvas1" id="txt1"/>
        <mx:Canvas x="10" y="36" width="308" height="135" id="canvas2">
            <mx:Text x="129" y="10" text="canvas2" id="txt2"/>
            <mx:Button x="118" y="55" label="Button2" id="btn2"/>
        </mx:Canvas>
        <mx:Button x="21" y="179" label="Button1" id="btn1"/>
        <mx:TextArea x="10" y="209" width="308" height="136" id="txtArea1"/>
    </mx:Canvas>
</mx:Application>