?简单说,target是事件的调用对象(event dispatcher),currentTarget是事件的处理对象(event processor)
以一个实例来说吧
?1?
<?
xml?version="1.0"?encoding="utf-8"
?>
?2?
<
mx:Application?
xmlns:mx
="http://www.adobe.com/2006/mxml"
?layout
="vertical"
?name
="app"
?3?
????initialize
="init()"
>
?4?
????
?5?
????
<
mx:Button?
id
="btn"
?name
="btn"
?label
="按钮1"
/>
?6?
????
?7?
????
<
mx:Button?
id
="btn2"
?name
="btn2"
?label
="按钮2"
?click
="clickHandler(event)"
?
/>
?8?
????
?9?
????
<
mx:Script
>
10?
????????
<![CDATA[
11?
????????????import?mx.controls.Alert;
12?
????????????private?function?init():?void
13?
????????????{
14?
????????????????addEventListener(MouseEvent.CLICK,?clickHandler);?????????????????
15?
????????????}
16?
????????????
17?
????????????private?function?clickHandler(event:?MouseEvent):?void
18?
????????????{
19?
????????????????Alert.show("target:?"?+?(event.target?as?DisplayObject).name
20?
????????????????????+?"ncurrentTarget:?"?+?(event.currentTarget?as?DisplayObject).name);
21?
????????????}
22?
????????
]]>
23?
????
</
mx:Script
>
24?
</
mx:Application
>
25?
说明:
- 点击btn,btn是事件发送者,因此,target是btn;
- app注册了事件监听器,用于监听MouseEvnet.Click事件,是事件处理者,因此currentTarget是app
- btn2自己注册了click事件,那么btn2既是事件发送者,又是处理者,因此,target和currentTarget都是btn2,这种情况下,两者是一致的
- 同时注意,由于app注册了鼠标点击事件,在点击btn2的时候,首先响应的是app的处理器,然后才是btn2的处理器