Outline UILabel text in UILabel Subclass

Question

I\'m trying hard to find a way to simply add an outline/stroke/contour to my UILabel text. Talking about a stroke around the letters of the text not around the background of

Answer 1

Update to Swift 5

This answer is built on Anandnimje and J.Doe answers, and is meant to update and streamline it to make the usage clearer and simpler.

Simply use these two functions:

func outline(string:String, font:String, size:CGFloat, outlineSize:Float, textColor:UIColor, outlineColor:UIColor) -> NSMutableAttributedString {
    return NSMutableAttributedString(string:string,
                                     attributes: outlineAttributes(font: UIFont(name: font, size: size)!,
                                                        outlineSize: outlineSize, textColor: textColor, outlineColor: outlineColor))
}

func outlineAttributes(font: UIFont, outlineSize: Float, textColor: UIColor, outlineColor: UIColor) -> [NSAttributedString.Key: Any]{
    return [
        NSAttributedString.Key.strokeColor : outlineColor,
        NSAttributedString.Key.foregroundColor : textColor,
        NSAttributedString.Key.strokeWidth : -outlineSize,
        NSAttributedString.Key.font : font
    ]
}

Then use outline with your labels as the following:

label.attributedText = outline(string: "Label Text", font: "HelveticaNeue", size: 14, outlineSize: 4, textColor: .white, outlineColor: .black)