CAAnimation-base class: timingFunction:指定动画,exa:"linear","easeIn","easeOut","easeInEaseOut","default" removedOnCompletion: 动画完成,是否回复原本状态 defaultValueForKey: key-value * CGPoint NSValue * CGSize NSValue * CGRect NSValue * CGAffineTransform NSValue * CATransform3D NSValue */