Create new UIImage by adding shadow to existing UIImage

Question

I\'ve taken a look at this question: UIImage Shadow Trouble

But the accepted answer didn\'t work for me.

What I\'m trying to do is take a UIImage and add a s

Answer 1

iOS8 / Swift version (made as an extension to UIImage):

extension UIImage {

    func addShadow(blurSize: CGFloat = 6.0) -> UIImage {

        let shadowColor = UIColor(white:0.0, alpha:0.8).cgColor

        let context = CGContext(data: nil,
                                width: Int(self.size.width + blurSize),
                                height: Int(self.size.height + blurSize),
                                bitsPerComponent: self.cgImage!.bitsPerComponent,
                                bytesPerRow: 0,
                                space: CGColorSpaceCreateDeviceRGB(),
                                bitmapInfo: CGImageAlphaInfo.premultipliedLast.rawValue)!

        context.setShadow(offset: CGSize(width: blurSize/2,height: -blurSize/2),
                          blur: blurSize,
                          color: shadowColor)
        context.draw(self.cgImage!,
                     in: CGRect(x: 0, y: blurSize, width: self.size.width, height: self.size.height),
                     byTiling:false)

        return UIImage(cgImage: context.makeImage()!)
    }
}

(converted from Laurent Etiemble's & capikaw answers)

EDIT 2016/10/31: converted to Swift 3, and removed all unnecessary stuff

Usage:

let sourceImage: UIImage(named: "some image")
let shadowImage = sourceImage.addShadow()