iOS -- 让图片顺时针持续旋转

    var angle = 0.0 //旋转角度
    override func awakeFromNib() {
    
    
        super.awakeFromNib()
        startAnimation()
    }
    func startAnimation() {
    
    
        let endAngle = CGAffineTransform(rotationAngle: CGFloat(angle*Double.pi/180.0))
        //0.05s 旋转10度 ，旋转完成后加10度 继续旋转
        UIView.animate(withDuration: 0.05) {
    
    
            self.imgView.transform = endAngle
        } completion: {
    
     (c) in
            self.angle += 10
            self.startAnimation()
        }
    }