Using cornerRadius on a UIImageView in a UITableViewCell

Question

I\'m using a UIImageView for each of my UITableViewCells, as thumbnails. My code uses SDWebImage to asynchronously grab those images from

Answer 1

Swift 3 version of thedeveloper3124's answer

func roundedImage(image: UIImage, completion: @escaping ((UIImage?)->(Void))) {
    DispatchQueue.global().async {
        // Begin a new image that will be the new image with the rounded corners
        // (here with the size of an UIImageView)
        UIGraphicsBeginImageContextWithOptions(image.size, false, image.scale)
        let rect = CGRect(x: 0, y: 0, width: image.size.width, height: image.size.height)

        // Add a clip before drawing anything, in the shape of an rounded rect
        UIBezierPath(roundedRect: rect, cornerRadius: image.size.width/2).addClip()

        // Draw your image
        image.draw(in: rect)

        // Get the image, here setting the UIImageView image
        guard let roundedImage = UIGraphicsGetImageFromCurrentImageContext() else {
            print("UIGraphicsGetImageFromCurrentImageContext failed")
            completion(nil)
            return
        }

        // Lets forget about that we were drawing
        UIGraphicsEndImageContext()

        DispatchQueue.main.async {
            completion(roundedImage)
        }
    }
}