extension String {
//MARK: Getting customized string
struct StringAttribute {
    var fontName = "HelveticaNeue-Bold"
    var fontSize: CGFloat?
    var initialIndexOftheText = 0
    var lastIndexOftheText: Int?
    var textColor: UIColor = .black
    var backGroundColor: UIColor = .clear
    var underLineStyle: NSUnderlineStyle = .styleNone
    var textShadow: TextShadow = TextShadow()

    var fontOfText: UIFont {
        if let font = UIFont(name: fontName, size: fontSize!) {
            return font
        } else {
            return UIFont(name: "HelveticaNeue-Bold", size: fontSize!)!
        }
    }

    struct TextShadow {
        var shadowBlurRadius = 0
        var shadowOffsetSize = CGSize(width: 0, height: 0)
        var shadowColor: UIColor = .clear
    }
}
func getFontifiedText(partOfTheStringNeedToConvert partTexts: [StringAttribute]) -> NSAttributedString {
    let fontChangedtext = NSMutableAttributedString(string: self, attributes: [NSFontAttributeName: UIFont(name: "HelveticaNeue-Bold", size: (partTexts.first?.fontSize)!)!])
    for eachPartText in partTexts {
        let lastIndex = eachPartText.lastIndexOftheText ?? self.count
        let attrs = [NSFontAttributeName : eachPartText.fontOfText, NSForegroundColorAttributeName: eachPartText.textColor, NSBackgroundColorAttributeName: eachPartText.backGroundColor, NSUnderlineStyleAttributeName: eachPartText.underLineStyle, NSShadowAttributeName: eachPartText.textShadow ] as [String : Any]
        let range = NSRange(location: eachPartText.initialIndexOftheText, length: lastIndex - eachPartText.initialIndexOftheText)
        fontChangedtext.addAttributes(attrs, range: range)
    }
    return fontChangedtext
}

}

//像下面这样使用它

    let someAttributedText = "Some   Text".getFontifiedText(partOfTheStringNeedToConvert: <#T##[String.StringAttribute]#>)

用我创建的库来解决您的问题将非常容易。它被称为Atributika。

let calculatedCoffee: Int = 768
let g = Style("g").font(.boldSystemFont(ofSize: 12)).foregroundColor(.red)
let all = Style.font(.systemFont(ofSize: 12))

let str = "\(calculatedCoffee)<g>g</g>".style(tags: g)
    .styleAll(all)
    .attributedString

label.attributedText = str

你可以在这里找到它https://github.com/psharanda/Atributika

斯威夫特4:

let attributes = [NSAttributedStringKey.font: UIFont(name: "HelveticaNeue-Bold", size: 17)!, 
                  NSAttributedStringKey.foregroundColor: UIColor.white]

 let attrString = NSAttributedString (
            string: "title-title-title",
            attributes: [NSAttributedStringKey.foregroundColor: UIColor.black])

细节

Swift 5.2, Xcode 11.4 (11E146)

解决方案

protocol AttributedStringComponent {
    var text: String { get }
    func getAttributes() -> [NSAttributedString.Key: Any]?
}

// MARK: String extensions

extension String: AttributedStringComponent {
    var text: String { self }
    func getAttributes() -> [NSAttributedString.Key: Any]? { return nil }
}

extension String {
    func toAttributed(with attributes: [NSAttributedString.Key: Any]?) -> NSAttributedString {
        .init(string: self, attributes: attributes)
    }
}

// MARK: NSAttributedString extensions

extension NSAttributedString: AttributedStringComponent {
    var text: String { string }

    func getAttributes() -> [Key: Any]? {
        if string.isEmpty { return nil }
        var range = NSRange(location: 0, length: string.count)
        return attributes(at: 0, effectiveRange: &range)
    }
}

extension NSAttributedString {

    convenience init?(from attributedStringComponents: [AttributedStringComponent],
                      defaultAttributes: [NSAttributedString.Key: Any],
                      joinedSeparator: String = " ") {
        switch attributedStringComponents.count {
        case 0: return nil
        default:
            var joinedString = ""
            typealias SttributedStringComponentDescriptor = ([NSAttributedString.Key: Any], NSRange)
            let sttributedStringComponents = attributedStringComponents.enumerated().flatMap { (index, component) -> [SttributedStringComponentDescriptor] in
                var components = [SttributedStringComponentDescriptor]()
                if index != 0 {
                    components.append((defaultAttributes,
                                       NSRange(location: joinedString.count, length: joinedSeparator.count)))
                    joinedString += joinedSeparator
                }
                components.append((component.getAttributes() ?? defaultAttributes,
                                   NSRange(location: joinedString.count, length: component.text.count)))
                joinedString += component.text
                return components
            }

            let attributedString = NSMutableAttributedString(string: joinedString)
            sttributedStringComponents.forEach { attributedString.addAttributes($0, range: $1) }
            self.init(attributedString: attributedString)
        }
    }
}

使用

let defaultAttributes = [
    .font: UIFont.systemFont(ofSize: 16, weight: .regular),
    .foregroundColor: UIColor.blue
] as [NSAttributedString.Key : Any]

let marketingAttributes = [
    .font: UIFont.systemFont(ofSize: 20.0, weight: .bold),
    .foregroundColor: UIColor.black
] as [NSAttributedString.Key : Any]

let attributedStringComponents = [
    "pay for",
    NSAttributedString(string: "one",
                       attributes: marketingAttributes),
    "and get",
    "three!\n".toAttributed(with: marketingAttributes),
    "Only today!".toAttributed(with: [
        .font: UIFont.systemFont(ofSize: 16.0, weight: .bold),
        .foregroundColor: UIColor.red
    ])
] as [AttributedStringComponent]
let attributedText = NSAttributedString(from: attributedStringComponents, defaultAttributes: defaultAttributes)

完整的示例

不要忘记在这里粘贴解决方案代码

import UIKit

class ViewController: UIViewController {

    private weak var label: UILabel!
    override func viewDidLoad() {
        super.viewDidLoad()
        let label = UILabel(frame: .init(x: 40, y: 40, width: 300, height: 80))
        label.numberOfLines = 2
        view.addSubview(label)
        self.label = label

        let defaultAttributes = [
            .font: UIFont.systemFont(ofSize: 16, weight: .regular),
            .foregroundColor: UIColor.blue
        ] as [NSAttributedString.Key : Any]

        let marketingAttributes = [
            .font: UIFont.systemFont(ofSize: 20.0, weight: .bold),
            .foregroundColor: UIColor.black
        ] as [NSAttributedString.Key : Any]

        let attributedStringComponents = [
            "pay for",
            NSAttributedString(string: "one",
                               attributes: marketingAttributes),
            "and get",
            "three!\n".toAttributed(with: marketingAttributes),
            "Only today!".toAttributed(with: [
                .font: UIFont.systemFont(ofSize: 16.0, weight: .bold),
                .foregroundColor: UIColor.red
            ])
        ] as [AttributedStringComponent]
        label.attributedText = NSAttributedString(from: attributedStringComponents, defaultAttributes: defaultAttributes)
        label.textAlignment = .center
    }
}

结果

Swift使用与Obj-C相同的NSMutableAttributedString。你通过传入计算值作为字符串来实例化它:

var attributedString = NSMutableAttributedString(string:"\(calculatedCoffee)")

现在创建带属性的g字符串。注意:UIFont.systemFontOfSize(_)现在是一个可失败的初始化式，所以在你可以使用它之前，它必须被解除包装:

var attrs = [NSFontAttributeName : UIFont.systemFontOfSize(19.0)!]
var gString = NSMutableAttributedString(string:"g", attributes:attrs)

然后追加:

attributedString.appendAttributedString(gString)

然后你可以像这样设置UILabel来显示NSAttributedString:

myLabel.attributedText = attributedString