¿Hay alguna manera de pausar una CABasicAnimation?

Tengo una animación básica de spinning del iPhone. ¿Hay alguna forma de que pueda "pausar" la animación para que se mantenga la posición de la vista? Supongo que una forma de hacer esto sería hacer que la animación se "complete" en lugar de llamar "remove" en ella, ¿cómo lo haría?

CABasicAnimation* rotationAnimation;
rotationAnimation = [CABasicAnimation animationWithKeyPath:@"transform.rotation.z"];
rotationAnimation.toValue = [NSNumber numberWithFloat: M_PI * 2];
rotationAnimation.duration = 100;
rotationAnimation.cumulative = YES;
rotationAnimation.repeatCount = HUGE_VALF;
rotationAnimation.removedOnCompletion = NO;
rotationAnimation.fillMode = kCAFillModeForwards;
[myView.layer addAnimation:rotationAnimation forKey:@"rotationAnimation"];
Author: mclaughlinj, 2010-02-21
Source

5 answers

Recientemente apareció la nota técnica de Apple QA1673 describe cómo pausar/reanudar la animación de la capa.

La lista de animaciones de pausa y reanudación se encuentra a continuación: 

-(void)pauseLayer:(CALayer*)layer
{
    CFTimeInterval pausedTime = [layer convertTime:CACurrentMediaTime() fromLayer:nil];
    layer.speed = 0.0;
    layer.timeOffset = pausedTime;
}

-(void)resumeLayer:(CALayer*)layer
{
    CFTimeInterval pausedTime = [layer timeOffset];
    layer.speed = 1.0;
    layer.timeOffset = 0.0;
    layer.beginTime = 0.0;
    CFTimeInterval timeSincePause = [layer convertTime:CACurrentMediaTime() fromLayer:nil] - pausedTime;
    layer.beginTime = timeSincePause;
}

Editar: iOS 10 introdujo una nueva API - UIViewPropertyAnimator que permite manejar animaciones de forma más interactiva, por ejemplo, hace que sea fácil pausar y reanudar la animación o 'buscarla' a algún valor de progreso particular.

 147
Author: Vladimir,
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2017-11-05 10:02:27

Respuesta Para Swift 3:

Créditos @ Vladimir

Código: 

 func pauseAnimation(){
  var pausedTime = layer.convertTime(CACurrentMediaTime(), fromLayer: nil)
  layer.speed = 0.0
  layer.timeOffset = pausedTime
}

func resumeAnimation(){
  var pausedTime = layer.timeOffset
  layer.speed = 1.0
  layer.timeOffset = 0.0
  layer.beginTime = 0.0
  let timeSincePause = layer.convertTime(CACurrentMediaTime(), fromLayer: nil) - pausedTime
  layer.beginTime = timeSincePause
}
 10
Author: Supratik Majumdar,
Warning: date(): Invalid date.timezone value 'Europe/Kyiv', we selected the timezone 'UTC' for now. in /var/www/agent_stack/data/www/ajaxhispano.com/template/agent.layouts/content.php on line 61
2016-11-03 11:20:30

Establezca el estado actual de la capa de su vista para que coincida con el estado de la presentationLayer, luego elimine la animación:

CALayer *pLayer = [myView.layer presentationLayer];
myView.layer.transform = pLayer.transform;
[myView.layer removeAnimationForKey:@"rotationAnimation"];
 6
Author: gerry3,
Warning: date(): Invalid date.timezone value 'Europe/Kyiv', we selected the timezone 'UTC' for now. in /var/www/agent_stack/data/www/ajaxhispano.com/template/agent.layouts/content.php on line 61
2010-02-23 01:55:38

Puede usar un temporizador o manejar el método delegado de animación:

- (void)animationDidStop:(CAAnimation *)anim finished:(BOOL)flag

Aquí está mi código:

// ...
[self startAnimation];
// ...

- (void)startAnimation {
CABasicAnimation* rotationAnimation;
rotationAnimation = [CABasicAnimation animationWithKeyPath:@"transform.rotation.z"];
rotationAnimation.fromValue = [NSNumber numberWithFloat:0];
rotationAnimation.toValue = [NSNumber numberWithFloat: M_2_PI];
rotationAnimation.duration = 1.0;
rotationAnimation.cumulative = YES;
// rotationAnimation.repeatCount = 0; // <- if repeatCount set to infinite, we'll not receive the animationDidStop notification when the animation is repeating
rotationAnimation.removedOnCompletion = NO;
rotationAnimation.fillMode = kCAFillModeForwards;
rotationAnimation.delegate = self; // <- hanlde the animationDidStop method
[myView.layer addAnimation:rotationAnimation forKey:@"rotationAnimation"];

}

- (void)animationDidStop:(CAAnimation *)anim finished:(BOOL)flag {
if (shouldContinueAnimation) // <- set a flag to start/stop the animation
    [self startAnimation];
}

Espero que pueda ayudarte.

 0
Author: h7ing,
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2011-12-12 08:02:48

El más simple

self.viewBall.layer.position = self.viewBall.layer.presentationLayer().position
 -1
Author: Chetan Prajapati,
Warning: date(): Invalid date.timezone value 'Europe/Kyiv', we selected the timezone 'UTC' for now. in /var/www/agent_stack/data/www/ajaxhispano.com/template/agent.layouts/content.php on line 61
2015-05-29 11:46:14