我在类函数中有以下代码:
public function foo():void
{
var timer:Timer = new Timer(10000,1);
timer.addEventListener(TimerEvent.TIMER_COMPLETE,onTimerComplete);
timer.start();
}
public function onTimerComplete(e:TimerEvent):void
{
// do stuff
}
上面的代码大部分时间都可以工作,但我担心的是如果计时器被垃圾收集会发生什么?是否有可能 onTimerComplete 永远不会触发,因为没有其他对计时器的引用?
我知道 timer 有一个内部处理程序列表,但这不会阻止它被 GC 处理。
最佳答案
网上有一些关于运行计时器从不被垃圾收集的引用资料,e.g. :
Just to be clear: even if you have no references to a Timer, as long as the timer is running, it will not be Garbage Collected (think of it as if the runtime was keeping a reference to running timers).
by Arno Gourdol on the Adobe AIR Team
但我一直无法找到权威来源。
可能最好不要依赖这种特殊行为,而是让
timer
一个类级别的变量,虽然。建议事件监听器阻止计时器被垃圾收集的答案是不正确的。引用是从计时器到监听器函数 (
onTimerComplete
),因此如果计时器可访问,则监听器函数不会被垃圾收集,反之亦然。这很容易测试:<?xml version="1.0" encoding="utf-8"?>
<s:Application
xmlns:s="library://ns.adobe.com/flex/spark"
creationComplete="application1_creationCompleteHandler(event)">
<fx:Script>
<![CDATA[
private var _gcTimer:Timer;
protected function application1_creationCompleteHandler(event:FlexEvent):void {
var timer:Timer = new Timer(30, 4);
timer.addEventListener(TimerEvent.TIMER, onTimer, false, 0, true);
var sprite:Sprite = new Sprite();
sprite.addEventListener(Event.ENTER_FRAME, onSprite, false, 0, true);
_gcTimer = new Timer(59, 1);
_gcTimer.addEventListener(TimerEvent.TIMER, garbageCollect);
timer.start();
_gcTimer.start();
}
private function onTimer(event:TimerEvent):void {
trace("timer");
}
private function onSprite(event:Event):void {
trace("sprite");
}
]]>
</fx:Script>
</s:Application>
输出:sprite
timer
sprite
timer
Collecting garbage
timer
timer
关于flash - 本地定时器对象事件处理程序,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/5891354/