旋转UIButton 360度

Question

我一直试图运行一个使用以下代码旋转我的UIButton 360度的动画：

UIView.animateWithDuration(3.0, animations: {
  self.vineTimeCapButton.transform = CGAffineTransformMakeRotation(CGFloat(M_PI*2))
  self.instagramTimeCapButton.transform = CGAffineTransformMakeRotation(CGFloat(M_PI*2))
})

然而，它不会旋转360度，因为UIButton已经在那个位置。

如何旋转我的UIButton 360度？

Answer 1

你可以用一个技巧:先开始180度旋转，然后360度旋转。使用2个延迟动画。尝尝这个。

UIView.animate(withDuration: 0.5) {
    self.view.transform = CGAffineTransform(rotationAngle: .pi)
}

UIView.animate(
    withDuration: 0.5,
    delay: 0.45,
    options: UIView.AnimationOptions.curveEaseIn
) {
    self.view.transform = CGAffineTransform(rotationAngle: 2 * .pi)
}

Answer 2

正如讨论过的here一样，您也可以使用CAAnimation。此代码适用于一个完整的360轮：

Swift 3

let fullRotation = CABasicAnimation(keyPath: "transform.rotation")
fullRotation.delegate = self
fullRotation.fromValue = NSNumber(floatLiteral: 0)
fullRotation.toValue = NSNumber(floatLiteral: Double(CGFloat.pi * 2))
fullRotation.duration = 0.5
fullRotation.repeatCount = 1
button.layer.add(fullRotation, forKey: "360")

您需要导入QuartzCore

import QuartzCore

而且您的ViewController需要符合CAAnimationDelegate

class ViewController: UIViewController, CAAnimationDelegate {

}

Answer 3

Swift 4：动画嵌套闭包优于动画延迟块。

UIView.animate(withDuration: 0.5, animations: { 
  button.transform = CGAffineTransform(rotationAngle: (CGFloat(Double.pi))) 
 }) { (isAnimationComplete) in

       // Nested Block
UIView.animate(withDuration: 0.5) { 
   button.transform = CGAffineTransform(rotationAngle: (CGFloat(Double.pi * 2)))
       }    
}