在Swift中将视图无限期旋转360度？

Question

我想将影像检视无限期旋转360度。

UIView.animate(withDuration: 2, delay: 0, options: [.repeat], animations: {
    self.view.transform = CGAffineTransform(rotationAngle: 6.28318530717959)
}, completion: nil)

我该怎么做？

Answer 1

从早期答案编译而来的Swift 2.x无限期旋转UIView的方法：

// Rotate <targetView> indefinitely
private func rotateView(targetView: UIView, duration: Double = 1.0) {
    UIView.animateWithDuration(duration, delay: 0.0, options: .CurveLinear, animations: {
        targetView.transform = CGAffineTransformRotate(targetView.transform, CGFloat(M_PI))
    }) { finished in
        self.rotateView(targetView, duration: duration)
    }
}

更新Swift 3.x

// Rotate <targetView> indefinitely
private func rotateView(targetView: UIView, duration: Double = 1.0) {
    UIView.animate(withDuration: duration, delay: 0.0, options: .curveLinear, animations: {
        targetView.transform = targetView.transform.rotated(by: CGFloat(M_PI))
    }) { finished in
        self.rotateView(targetView: targetView, duration: duration)
    }
}