从背面退回时，对无缝循环中的图像进行无限滚动动画不起作用

可能重复：

我有以下代码运行同一图像的无穷循环

I have the following code that run an endless loop of the same image

问题是当用户最小化应用程序时，回到它，图像停止动画，它完全消失

the problem is when the user minimize the application, and get back to it, the image stop animating and it totally disappear

这是我的代码：

-(void)cloudScroll
{
UIImage *cloudsImage = [UIImage imageNamed:@"TitleClouds.png"];
UIColor *cloudPattern = [UIColor colorWithPatternImage:cloudsImage];
CALayer *cloud = [CALayer layer];
cloud.backgroundColor = cloudPattern.CGColor;
cloud.transform = CATransform3DMakeScale(1, -1, 1);
cloud.anchorPoint = CGPointMake(0, 1);
CGSize viewSize = self.cloudsImageView.bounds.size;
cloud.frame = CGRectMake(0, 0, cloudsImage.size.width + viewSize.width, viewSize.height);
[self.cloudsImageView.layer addSublayer:cloud];

CGPoint startPoint = CGPointZero;
CGPoint endPoint = CGPointMake(-cloudsImage.size.width, 0);
CABasicAnimation *animation = [CABasicAnimation animationWithKeyPath:@"position"];
animation.timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionLinear];
animation.fromValue = [NSValue valueWithCGPoint:startPoint];
animation.toValue = [NSValue valueWithCGPoint:endPoint];
animation.repeatCount = HUGE_VALF;
animation.duration = 3.0;
[cloud addAnimation:animation forKey:@"position"];
}

编辑：
可能的重复项在无缝循环中对图像进行无限滚动动画