Timer使用小结

/**
 * Constructs a new Timer object with the specified delay
 * and repeatCount states.
 * 
 *   The timer does not start automatically; you must call the start() method
 * to start it.
 * @param delayThe delay between timer events, in milliseconds. A delay lower than 20 milliseconds is not recommended. Timer frequency
 *   is limited to 60 frames per second, meaning a delay lower than 16.6 milliseconds causes runtime problems.
 * @param repeatCountSpecifies the number of repetitions.
 *   If zero, the timer repeats infinitely. 
 *   If nonzero, the timer runs the specified number of times and then stops.
 * @langversion 3.0
 * @playerversion Flash 9
 * @playerversion Lite 4
 * @throws Error if the delay specified is negative or not a finite number
 */
public function Timer (delay:Number, repeatCount:int=0);

var timer:Timer = new Timer(20, 0);

timer.addEventListener(TimerEvent.TIMER, timerListener);

timer.start();

使用Timer作为计时器使用时，参数delay最好不用小于20毫秒，否则容易出现运行问题。