如何在Swift中旋转UIButton？

Question

I used to rotate an image this way:

self.image.transform = CGAffineTransformRotate(self.image.transform, 
                                      CGFloat(M_PI))

But this code doesn't work for a button:

let rotateAnimation = CABasicAnimation(keyPath: "transform.rotation")
rotateAnimation.fromValue = 0.0
rotateAnimation.toValue = CGFloat(M_PI)

But I don't know how to assign that rotation to the button. How can I do it?

Answer 1

You have created a CABasicAnimation . You should now add it to a CALayer . Try using this code:

button.layer.addAnimation(rotateAnimation, forKey: "myAnimationKey");

Set a duration this way:

let duration = 1.0
rotateAnimation.duration = duration

A UIButton has a layer Property.

Answer 2

Just add your animation to the layer of your button.

//If you want a duration
rotateAnimation.duration = yourDuration

//You can set a key, but must not.
button.layer.addAnimation(rotateAnimation, forKey: nil)