在ActionScript3中，如何计算鼠标按住时间...我是actionscript 3的新手

import flash.utils.getTimer;
import flash.events.MouseEvent;

var mouseDownTime:int = 0;

stage.addEventListener(MouseEvent.MOUSE_DOWN, onMouseDown);
stage.addEventListener(MouseEvent.MOUSE_UP, onMouseUp);

function onMouseDown(event:MouseEvent):void {
    mouseDownTime = getTimer();
}

function onMouseUp(event:MouseEvent):void {
    var mouseUpTime:int = getTimer();
    var pressDuration:int = mouseUpTime - mouseDownTime;
    trace("鼠标按住时间：" + pressDuration + "毫秒");
    // 在这里可以根据需要进行后续操作
}