一个桢动画学习

UIView.animateKeyframesWithDuration(2.0, delay: 0.0, options: UIViewKeyframeAnimationOptions.LayoutSubviews, animations: { () -> Void in
            UIView.addKeyframeWithRelativeStartTime(0.0, relativeDuration: 0.5, animations: { () -> Void in
                self.imageView.center = CGPointMake(100, 100)
            })
            UIView.addKeyframeWithRelativeStartTime(0.0, relativeDuration: 0.5, animations: { () -> Void in
                let rotation:CGFloat = CGFloat(45*M_PI / 180.0)
                self.imageView.transform = CGAffineTransformMakeRotation(rotation)
            })
            UIView.addKeyframeWithRelativeStartTime(0.0, relativeDuration: 0.5, animations: { () -> Void in
                self.imageView.backgroundColor = UIColor.greenColor()
            })
            }) { (finished:Bool) -> Void in
                print("Animation completed:\(finished)")
        }