WWW : World Wide Wonsama

e.eventPhase == EventPhase.AT_TARGET 를 통하여 구분 처리 해준다.
그러면 _titleBar._btn1을 클릭하였을 경우 btnClick만 호출된다.

만약 위 구문을 빼고 코딩을 하였을 경우에는
_titleBar._btn1 을 클릭하였을 경우 titleDown -> titleUp - > btnClick 순서대로 함수가 호출된다.

_titleBar.addEventListener(MouseEvent.MOUSE_UP, titleUp);
function titleUp(e:Event):void{
    if (e.eventPhase == EventPhase.AT_TARGET) {
        // event came from object
        // addEventListener was used with and
        // is not result of propagation
        trace("titleUp");
    }
   
}
_titleBar.addEventListener(MouseEvent.MOUSE_DOWN, titleDown);
function titleDown(e:Event):void{
    if (e.eventPhase == EventPhase.AT_TARGET) {
        // event came from object
        // addEventListener was used with and
        // is not result of propagation
        trace("titleDown");
    }
   
}

_titleBar._btn1.addEventListener(MouseEvent.CLICK, btnClick);
function btnClick(e:Event):void{
    if (e.eventPhase == EventPhase.AT_TARGET) {
        // event came from object
        // addEventListener was used with and
        // is not result of propagation
        trace("btnClick");
    }       
}

참조 : http://www.senocular.com/flash/tutorials/as3withflashcs3/?page=3