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I'm using GreenSock's TweenMax in AS3, Flash AIR 3.2 for iOS. I'm trying to get a string of text to start fading using the autoAlpha plugin at a certain point (such as after it reaches the middle of the tween) during the movement tween, and not from start to finish. At the moment it is tweening both the movement and alpha from the start position to finish. Is this possible to do?

TweenMax.to(textOne, 14, {x:xScreenPos - 150, ease:SlowMo.ease.config(1, 0), repeat:-1, autoAlpha:0.5});

EDIT: This is the current code with the functions and syntax fixed, but it does not work for some reason. There is still a movement tween, but the alpha is not tweening anymore. The logic seems correct though. (alpha now replaces autoAlpha because it works over the latter).

import com.greensock.events.TweenEvent;
import com.greensock.TweenMax;

var _middle:Boolean = false;
var _tween:TweenMax;

public function run():void {
    _tween = TweenMax.to(textOne, 14, {x:xScreenPosEnd, ease:SlowMo.ease.config(1, 0), repeat:-1});
    _tween.addEventListener(TweenEvent.UPDATE, updateListener);
    _tween.addEventListener(TweenEvent.REPEAT, repeatListener);
}

function updateListener(e:TweenEvent):void {
    if(_tween.totalProgress() > 0.5 && _middle == false) {
        TweenMax.to(textOne, 7, {ease:SlowMo.ease.config(1, 0), repeat:-1, alpha:0});
        _middle = true;
    }
}

function repeatListener(e:TweenEvent):void {
    textOne.alpha = 1.0;
    _middle = false;
}

EDIT: totalProgress() has been replaced with progress() and the alpha tweens again – but there's another problem with the alpha tween. I've traced out both textOne.alpha and _tween.progress() to debug. Either it's because of the single-threaded nature of AS3, it is messing up the call logic at the end of each loop... because there is a delayed end to the alpha tween, the REPEAT call cannot set the alpha to 1 in time, before the progress tween starts. Or it's something in the logic which is wrong. I tried setting the (alpha) tween time of TextOne to 6, but it still messes it up.

Actually, I'm not too sure what's going on after thinking about it a bit more. It makes NO logical sense. The first alpha tween is fine, then it messes up on repeat and repeats the alpha tween (but at the wrong progress() position) a few times, then stays at 0 forever. Here's a snapshot of the traces:

ALPHA: 0.0078125
PROGRESS: 0.9979285714285714
MIDDLE: true
...
ALPHA: 0
PROGRESS: 0.9992857142857144
MIDDLE: true

ALPHA: 0
PROGRESS: 0.00028571428571438115
MIDDLE: true

ALPHA: 0
PROGRESS: 0.000714285714285826
MIDDLE: false

ALPHA: 0.99609375
PROGRESS: 0.0015714285714287155
MIDDLE: false
...
ALPHA: 0.1015625
PROGRESS: 0.4504285714285715
MIDDLE: false

ALPHA: 0.09765625
PROGRESS: 0.4515714285714285
MIDDLE: false
...
ALPHA: 0.00390625
PROGRESS: 0.4992142857142858
MIDDLE: false

ALPHA: 0
PROGRESS: 0.5003571428571431
MIDDLE: false

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2 回答 2

1

只需使用两个TweenMax.to()电话。给一个delay:参数和一个较小的值duration。

于 2013-02-04T19:12:27.553 回答
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您可以保存第一个 TweenMax.to 并为 TweenEvent.UPDATE 事件附加一个侦听器，这样您就可以在每次 tween 更改值时调用一个函数。

然后获取 currentProgress 的值并检查该值是否高于 0.5（这意味着它超过了补间的中间）并开始第二个补间。您需要一个 bool 变量，因此每个中间补间只执行一次。

您可以为 TweenEvent.REPEAT 事件添加另一个侦听器，以便在补间重复时将 alpha 对象的值重置为 1。

var middle:Boolean = false;
TweenMax tween = TweenMax.to(textOne, 14, {x:xScreenPos - 150, ease:SlowMo.ease.config(1, 0), repeat:-1});
tween.addEventListener( TweenEvent.UPDATE, updateListener );
tween.addEventListener( TweenEvent.REPEAT, repeatListener );

function updateListener( e:TweenEvent ):void
{
  if( tween.currentProgress > 0.5 && middle == false )
  {
   TweenMax.to(textOne, 7, {ease:SlowMo.ease.config(1, 0), repeat:0, autoAlpha:0});
   middle = true;
  }
}

function repeatListener( e:TweenEvent ):void
{
 textOne.alpha = 1.0;
 middle = false;
}

希望这可以帮助

于 2013-02-08T18:20:07.027 回答