ios - cabasicanimation 需要重置

Question

我有 3 个颜色条的 3 个 CABasicAnimation，它们相互跟随。第三个完成后，3 个小节将停留在其最终位置。到这里为止，一切都很好，这是代码:

- (void)animationDidStop:(CABasicAnimation *)theAnimation finished:(BOOL)flag {
    NSString* value = [theAnimation valueForKey:@"id"];
    if([value isEqualToString:@"position1"]){
        [self playVideoAtIndex:1];
    }
    else if([value isEqualToString:@"position2"]){
        [self playVideoAtIndex:2];
    }
    else if([value isEqualToString:@"position3"]){

    }
}

在此之前，我创建了 3 个这样的动画:

-(void)createAnimationAtIndex:(NSInteger)index{
UILabel *label = (UILabel *)[barLabelArray objectAtIndex:index];
if(index==0){
    CABasicAnimation *animation = [CABasicAnimation animationWithKeyPath:@"position"];
    animation.delegate = self;
    //SOMETHING HERE
    [label.layer addAnimation:animation forKey:@"position1"];
}
else if(index==1){
    CABasicAnimation *animation = [CABasicAnimation animationWithKeyPath:@"position"];
    animation.delegate = self;
    //SOMETHING HERE
    [self.delegate startPlayVideoAtIndex:1];
    [label.layer addAnimation:animation forKey:@"position2"];
}
else if(index==2){
    CABasicAnimation *animation = [CABasicAnimation animationWithKeyPath:@"position"];
    animation.delegate = self;
    //SOMETHING HERE
    [label.layer addAnimation:animation forKey:@"position3"];
}

因此，如果我等到所有动画停止，当我回来时，它们将再次正常启动动画。但有时我需要在中间停止动画。然后当我回来重新开始动画时，一切都搞砸了。这是停止动画的代码:

-(void)reset{
    for(UILabel *label in barLabelArray){
        [label.layer removeAllAnimations];
    }
}

那么你知道我在这里做错了什么以及如何解决它吗？谢谢!!

Answer 1

有一种方法可以暂停和恢复任何动画。这里有几个很好的字符串，如果我理解正确的话，可以帮助你

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

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