Ответ 1

Использовать NSMutableAttributedString

Небольшой пример

let yourAttributes = [NSForegroundColorAttributeName: UIColor.blackColor(), NSFontAttributeName: UIFont.systemFontOfSize(15)]
let yourOtherAttributes = [NSForegroundColorAttributeName: UIColor.redColor(), NSFontAttributeName: UIFont.systemFontOfSize(25)]

let partOne = NSMutableAttributedString(string: "This is an example ", attributes: yourAttributes)
let partTwo = NSMutableAttributedString(string: "for the combination of Attributed String!", attributes: yourOtherAttributes)

let combination = NSMutableAttributedString()

combination.appendAttributedString(partOne)
combination.appendAttributedString(partTwo) 

Swift 3

let yourAttributes = [NSForegroundColorAttributeName: UIColor.black, NSFontAttributeName: UIFont.systemFont(ofSize: 15)]
let yourOtherAttributes = [NSForegroundColorAttributeName: UIColor.red, NSFontAttributeName: UIFont.systemFont(ofSize: 25)]

let partOne = NSMutableAttributedString(string: "This is an example ", attributes: yourAttributes)
let partTwo = NSMutableAttributedString(string: "for the combination of Attributed String!", attributes: yourOtherAttributes)

let combination = NSMutableAttributedString()

combination.append(partOne)
combination.append(partTwo)

combination представляет вашу окончательную строку, которая содержит обе формы, предоставленные yourAttributes и yourOtherAttributes

Ответ 2

@glace ответ, модифицированный, чтобы избежать пустого объявления NSMutableAttributedString. Действительно в Swift 3.1:

let yourAttributes = [NSForegroundColorAttributeName: UIColor.blackColor(), NSFontAttributeName: UIFont.systemFontOfSize(15)]
let yourOtherAttributes = [NSForegroundColorAttributeName: UIColor.redColor(), NSFontAttributeName: UIFont.systemFontOfSize(25)]

let partOne = NSMutableAttributedString(string: "This is an example ", attributes: yourAttributes)
let partTwo = NSMutableAttributedString(string: "for the combination of Attributed String!", attributes: yourOtherAttributes)

partOne.append(partTwo)

partOne - это ваша последняя строка со всеми атрибутами. Никаких промежуточных "комбайнер" не требуется.

Swift 4

let yourAttributes: [NSAttributedString.Key: Any] = [.foregroundColor: UIColor.black, .font: UIFont.systemFont(ofSize: 15)]
let yourOtherAttributes: [NSAttributedString.Key: Any] = [.foregroundColor: UIColor.red, .font: UIFont.systemFont(ofSize: 25)]

let partOne = NSMutableAttributedString(string: "This is an example ", attributes: yourAttributes)
let partTwo = NSMutableAttributedString(string: "for the combination of Attributed String!", attributes: yourOtherAttributes)

partOne.append(partTwo)

Ответ 3

используя расширение,

extension NSMutableAttributedString{
    func getAttributedStringByAppending(attributedString:NSMutableAttributedString) -> NSMutableAttributedString{
        let newAttributedString = NSMutableAttributedString()
        newAttributedString.append(self)
        newAttributedString.append(attributedString)
        return newAttributedString
    }
}

Использование: attribuStString1, attribuStString2 два NSMutableAttributedString, затем

let combinedAttributedString = attributedString1.getAttributedStringByAppending(attributedString: attributedString2)

Ответ 4

Swift 5

Согласно ответу "glace", я просто обновляю атрибут шрифта и версию swift.

    let boldFontAttributes = [NSAttributedString.Key.foregroundColor: UIColor.black, NSAttributedString.Key.font: UIFont.boldSystemFont(ofSize: 17)]
    let normalFontAttributes = [NSAttributedString.Key.foregroundColor: UIColor.darkGray, NSAttributedString.Key.font: UIFont.systemFont(ofSize: 15)]
    let partOne = NSMutableAttributedString(string: "This is an example ", attributes: boldFontAttributes)
    let partTwo = NSMutableAttributedString(string: "for the combination of Attributed String!", attributes: normalFontAttributes)

    let combination = NSMutableAttributedString()

    combination.append(partOne)
    combination.append(partTwo)
    lblUserName.attributedText = combination