How to set kerning in iPhone UILabel

Question

I am developing an iPhone app, and I want to set kerning in UILabel. The code I\'ve written (possibly around kCTKernAttributeName) seems to be in error. How mig

Answer 1

Before:

After:

Here's a Swift 3 extension that let's you set a UILabel's kerning via code or storyboard:

extension UILabel {

    @IBInspectable var kerning: Float {
        get {
            var range = NSMakeRange(0, (text ?? "").count)
            guard let kern = attributedText?.attribute(NSAttributedStringKey.kern, at: 0, effectiveRange: &range),
                let value = kern as? NSNumber
                else {
                    return 0
            }
            return value.floatValue
        }
        set {
            var attText:NSMutableAttributedString

            if let attributedText = attributedText {
                attText = NSMutableAttributedString(attributedString: attributedText)
            } else if let text = text {
                attText = NSMutableAttributedString(string: text)
            } else {
                attText = NSMutableAttributedString(string: "")
            }

            let range = NSMakeRange(0, attText.length)
            attText.addAttribute(NSAttributedStringKey.kern, value: NSNumber(value: newValue), range: range)
            self.attributedText = attText
        }
    }
}

Demo usage:

myLabel.kerning = 3.0

or

The demo uses 3.0 kerning for drama, but I've found 0.1 - 0.8 tends to work well in practice.