如果需要，请确保导入QuarzCore。

 func maskRoundedImage(image: UIImage, radius: CGFloat) -> UIImage {
        let imageView: UIImageView = UIImageView(image: image)
        let layer = imageView.layer
        layer.masksToBounds = true
        layer.cornerRadius = radius
        UIGraphicsBeginImageContext(imageView.bounds.size)
        layer.render(in: UIGraphicsGetCurrentContext()!)
        let roundedImage = UIGraphicsGetImageFromCurrentImageContext()
        UIGraphicsEndImageContext()
        return roundedImage!
    }