Moving an object (UIButton) through a circular path by keeping the parent view static

How do 开发者_开发问答I move some buttons into a circular path (using the center of an circular UIView) by 45 degree each time any of the buttons is clicked? You can say it's just like JOG WHEEL.

1. Create a CGPathRef that contains the path along which you want to animate the view.
2. Create a CAKeyframeAnimation.
3. Assign the path to the animation.path property.
4. Add the animation to the view's layer.