Comment puis-je modifier l'espacement des lettres dans un UILabel?

Vous pouvez utiliser le NSKernAttributeName attribut sur un attribué chaîne:

UILabel *label = [UILabel new];

NSMutableAttributedString *text = [[NSMutableAttributedString alloc] 
                                   initWithString:@"127"];

//The value paramenter defines your spacing amount, and range is 
//the range of characters in your string the spacing will apply to. 
//Here we want it to apply to the whole string so we take it from 0 to text.length.
[text addAttribute:NSKernAttributeName 
             value:@-0.5 
             range:NSMakeRange(0, text.length)];

[label setAttributedText:text];

Vous pouvez utiliser un NSAttributedString et de jouer avec les NSKernAttributeName attribut. La valeur par défaut est 0 de sorte que vous souhaitez définir un nombre négatif.

https://developer.apple.com/library/mac/documentation/Cocoa/Reference/Foundation/Classes/NSAttributedString_Class/#//apple_ref/doc/constant_group/Character_Attributes

en Obj-C, vous pouvez faire quelque chose comme ceci:

NSMutableAttributedString* attrStr = [[NSMutableAttributedString alloc]initWithString: @"Test test test test "];
[attrStr addAttribute:NSKernAttributeName value:@(4.0) range:NSMakeRange(0, attrStr.length)];

label.attributedText = attrStr;

en rapidement vous pourriez faire quelque chose comme ceci:

let myTitle = "my title"
let titleLabel = UILabel()
let attributes: NSDictionary = [
    NSFontAttributeName:UIFont(name: "FONT_NAME", size: TEXT_SIZE),
    NSKernAttributeName:CGFloat(2.0)
]

let attributedTitle = NSAttributedString(string: myTitle, attributes:attributes as? [String : AnyObject])

titleLabel.attributedText = attributedTitle

Si vous souhaitez appliquer l'espacement des lettres de l'attribut de tous les UILabels dans Interface Builder, sans modifier quoi que ce soit (pour la police):

Swift 4:

/**
 * Applies letter spacing to selected fonts in UILabels from IB.
 *
 * - author Alexander Volkov
 * - version 1.0
 */
extension UILabel {

    ///Applies letter spacing
    open override func awakeFromNib() {
        super.awakeFromNib()
        applyLetterSpacing()
    }

    ///Applies letter spacing
    ///
    ///- Parameter aDecoder: the decoder
    ///- Returns: UILabel instance
    open override func awakeAfter(using aDecoder: NSCoder) -> Any? {
        let label = super.awakeAfter(using: aDecoder)
        self.applyLetterSpacing()
        return label
    }


    ///Applies letter spacing
    func applyLetterSpacing() {
        if font.fontName.contains("Oswald", caseSensitive: false) {
            let characterSpacing: CGFloat = 1
            let string = NSMutableAttributedString(string: self.text!)
            string.addAttribute(.kern, value: characterSpacing, range: NSRange(location: 0, length: string.length - 1))
            self.attributedText = string
        }
    }
}

J'ai pris la réponse de @J2K est traduite dans un Swift 4.2 extension.

///Set the text of the label but altering the kerning so that you can control the space between each characters.
///
///- Parameters:
///  - text: New content of the label
///  - kerning: Set a value between 0 and 1 to lower the space between characters. Above 0, spacing will be increased. 0 disables kerning.
extension UILabel {

    func set(text: String, withKerning kerning: CGFloat) {
        let attributedString = NSMutableAttributedString(string: text)

        //The value parameter defines your spacing amount, and range is
        //the range of characters in your string the spacing will apply to.
        //Here we want it to apply to the whole string so we take it from 0 to text.count.
        attributedString.addAttribute(NSAttributedString.Key.kern, value: kerning, range: NSMakeRange(0, text.count))

        attributedText = attributedString
    }

}

De l'essayer. Il va ajouter de l'espacement des caractères que vous attribuez, soit vous définissez un simple texte ou attribuée texte. https://stackoverflow.com/a/49929848/4559803