let descriptionString = String(format: "localised_key".localized(), Harsh, 10) let description = NSMutableAttributedString(string: descriptionString, attributes: [NSAttributedString.Key.font: UIFont(name: "NotoSans-Regular", size: 15.7)!, NSAttributedString.Key.foregroundColor: UIColor(rgb: 0x000b38), NSAttributedString.Key.kern: 0.5]) let rangeName = descriptionString.range(of: "Harsh") let rangeClass = descriptionString.range(of: "10") let nsrangeName = NSRange(rangeName!, in: descriptionString) let nsrangeClass = NSRange(rangeClass!, in: descriptionString) description.addAttributes([NSAttributedString.Key.font: UIFont(name: "NotoSans-Bold", size: 15.7)!, NSAttributedString.Key.foregroundColor: UIColor(rgb: 0x000b38), NSAttributedString.Key.kern: 0.5], range: nsrangeName) description.addAttributes([NSAttributedString.Key.font: UIFont(name: "NotoSans-Bold", size: 15.7)!, NSAttributedString.Key.foregroundColor: UIColor(rgb: 0x000b38), NSAttributedString.Key.kern: 0.5], range: nsrangeClass)

para más referencias, use este

let withFormat = "my name is %@ and i study in class %@"

Hay diferentes formas de hacerlo, pero en mi opinión, una de las más fáciles sería usar etiquetas:

Use etiquetas alrededor de los marcadores de posición (y otras partes si es necesario):

 let withFormat = "my name is <b>%@</b> and i study in class <b>%@</b>" let withFormat = "my name is [b]%@[/b] and i study in class [b]%@[/b]" let withFormat = "my name is **%@** and i study in class **%@**"

Las etiquetas pueden ser HTML, Markdown, BBCode o cualquier otra personalizada que desee, luego, reemplace los valores de marcador de posición:

 let localized = String(format: withFormat, value1, value2)

Ahora, dependiendo de cómo quieras hacerlo, o qué etiqueta usaste, puedes usar el inicio de NSAttributedString desde HTML, Markdown, etc., o simplemente usando NSAttributedString(string: localized) , busca las etiquetas y aplica el render efecto necesario.

Aquí hay un pequeño ejemplo:

 let tv = UITextView(frame: CGRect(x: 0, y: 0, width: 300, height: 130)) tv.backgroundColor = .orange let attributedString = NSMutableAttributedString() let htmled = String(format: "my name is <b>%@</b> and i study in class <b>%@</b>", arguments: ["Alice", "Wonderlands"]) let markdowned = String(format: "my name is **%@** and i study in class **%@**", arguments: ["Alice", "Wonderlands"]) let bbcoded = String(format: "my name is [b]%@[/b] and i study in class [b]%@[/b]", arguments: ["Alice", "Wonderlands"]) let separator = NSAttributedString(string: "\n\n") let html = try! NSAttributedString(data: Data(htmled.utf8), options: [.documentType : NSAttributedString.DocumentType.html], documentAttributes: nil) attributedString.append(html) attributedString.append(separator) let markdown = try! NSAttributedString(markdown: markdowned, baseURL: nil) //iO15+ attributedString.append(markdown) attributedString.append(separator) let bbcode = NSMutableAttributedString(string: bbcoded) let regex = try! NSRegularExpression(pattern: "\\[b\\](.*?)\\[\\/b\\]", options: []) let matches = regex.matches(in: bbcode.string, options: [], range: NSRange(location: 0, length: bbcode.length)) let boldEffect: [NSAttributedString.Key: Any] = [.font: UIFont.boldSystemFont(ofSize: 12)] //We use reversed() because if you replace the first one, you'll remove [b] and [/b], meaning that the other ranges will be affected, so the trick is to start from the end matches.reversed().forEach { aMatch in let valueRange = aMatch.range(at: 1) //We use the regex group let replacement = NSAttributedString(string: bbcode.attributedSubstring(from: valueRange).string, attributes: boldEffect) bbcode.replaceCharacters(in: aMatch.range, with: replacement) } attributedString.append(bbcode) tv.attributedText = attributedString

Producción: