iOS 核心动画KeyPath取值

animationWithKeyPath的值：

transform.scale = 比例轉換
transform.scale.x = 闊的比例轉換
transform.scale.y = 高的比例轉換
transform.rotation.z = 平面圖的旋轉
opacity = 透明度
margin
zPosition
backgroundColor    背景颜色
cornerRadius    圆角
borderWidth
bounds
contents
contentsRect
cornerRadius
frame
hidden
mask
masksToBounds
opacity
position
shadowColor
shadowOffset
shadowOpacity
shadowRadius

注意这几条属性别忘记:

theAnimation.removedOnCompletion = NO;
theAnimation.fillMode = kCAFillModeForwards;
theAnimation.autoreverses = NO;