如何在ActionScript 2或3中等待3秒？

Question

是否有任何方法可以在ActionScript中实现等待3秒,但是保持在同一个函数中？我看过setInterval,setTimeOut和类似的函数,但我真正需要的是:

public function foo(param1, param2, param3) {
  //do something here
  //wait for 3 seconds
  //3 seconds have passed, now do something more
}

万一你想知道为什么我需要这个 - 这是一个法律要求,不,我不能改变它.

Answer 1

使用Timer3秒后调用一个函数.

var timer:Timer = new Timer(3000);
timer.addEventListener(TimerEvent.TIMER, callback); // will call callback()
timer.start();

要正确执行此操作,您应该将计时器创建为实例变量,以便在调用函数时删除侦听器和计时器实例,以避免泄漏.

class Test {
    private var timer:Timer = new Timer(3000);

    public function foo(param1:int, param2:int, param3:int):void {
        // do something here
        timer.addEventListener(TimerEvent.TIMER, fooPartTwo);
        timer.start();
    }

    private function fooPartTwo(event:TimerEvent):void {
        timer.removeEventListener(TimerEvent.TIMER, fooPartTwo);
        timer = null;
        // 3 seconds have passed, now do something more
    }
}

您还可以在函数内使用另一个函数foo并保留范围,因此您不需要传递变量.

function foo(param1:int, param2:int, param3:int):void {
    var x:int = 2; // you can use variables as you would normally

    // do something here

    var timer:Timer = new Timer(3000);
    var afterWaiting:Function = function(event:TimerEvent):void {
       timer.removeEventListener(TimerEvent.TIMER, afterWaiting);
       timer = null;

       // 3 seconds have passed, now do something more

       // the scope is retained and you can still refer to the variables you
       // used earlier
       x += 2;
    }

    timer.addEventListener(TimerEvent.TIMER, afterWaiting);
    timer.start();
}