对事件三个阶段的认识

<?xml version="1.0"?>
<!-- events/KeyboardEventPrecedence.mxml -->
<mx:Application xmlns:mx="http://www.adobe.com/2006/mxml" creationComplete="initApp();">
    <mx:Script><![CDATA[
        private function initApp():void {
             /**
        	 * useCapture=true 只在捕获阶段处理事件，先捕获父后捕获子
        	 * 结果 target + currentTarget
        	 * flex_test0.my_vbox.my_textinput.UITextField7(flex_test0): 85/117
        	 * flex_test0.my_vbox.my_textinput.UITextField7(flex_test0.my_vbox): 85/117
        	 * flex_test0.my_vbox.my_textinput.UITextField7(flex_test0.my_vbox.my_textinput): 85/117
        	 */
            application.addEventListener(KeyboardEvent.KEY_UP, keyHandler,true);
            my_vbox.addEventListener(KeyboardEvent.KEY_UP, keyHandler,true);
            my_textinput.addEventListener(KeyboardEvent.KEY_UP, keyHandler,true);
             /**
        	 * useCapture=false(默认) 只在目标、冒泡阶段处理事件，先捕获子后捕获父
        	 * 结果 target + currentTarget
        	 * flex_test0.my_vbox.my_textinput.UITextField7(flex_test0.my_vbox.my_textinput): 85/117
        	 * flex_test0.my_vbox.my_textinput.UITextField7(flex_test0.my_vbox): 85/117
        	 * flex_test0.my_vbox.my_textinput.UITextField7(flex_test0): 85/117
        	 */
            application.addEventListener(KeyboardEvent.KEY_UP, keyHandler);
            my_vbox.addEventListener(KeyboardEvent.KEY_UP, keyHandler);
            my_textinput.addEventListener(KeyboardEvent.KEY_UP, keyHandler);
            
            my_textinput.setFocus();
        }

        private function keyHandler(event:KeyboardEvent):void {
            ta1.text += event.target + "(" + event.currentTarget + "): " + 
                event.keyCode + "/" + event.charCode + "\n";
        }
    ]]></mx:Script>
    
    <mx:VBox id="my_vbox">
        <mx:TextInput id="my_textinput"/>
    </mx:VBox>

    <mx:TextArea id="ta1" height="300" width="550"/>

</mx:Application>