SWIFT 4.2

let main_string = "Hello World"
let string_to_color = "World"

let range = (main_string as NSString).range(of: string_to_color)

let attribute = NSMutableAttributedString.init(string: main_string)
attribute.addAttribute(NSAttributedString.Key.foregroundColor, value: UIColor.red , range: range)


txtfield1 = UITextField.init(frame:CGRect(x:10 , y:20 ,width:100 , height:100))
txtfield1.attributedText = attribute

克里斯的回答对我来说是一个很大的帮助,所以我用他的方法变成了一个我可以重用的功能.这让我为子串指定颜色,同时为字符串的其余部分添加另一种颜色.

static func createAttributedString(fullString: String, fullStringColor: UIColor, subString: String, subStringColor: UIColor) -> NSMutableAttributedString
{
    let range = (fullString as NSString).rangeOfString(subString)
    let attributedString = NSMutableAttributedString(string:fullString)
    attributedString.addAttribute(NSForegroundColorAttributeName, value: fullStringColor, range: NSRange(location: 0, length: fullString.characters.count))
    attributedString.addAttribute(NSForegroundColorAttributeName, value: subStringColor, range: range)
    return attributedString
}

Swift 2.1更新:

 let text = "We tried to make this app as most intuitive as possible for you. If you have any questions don't hesitate to ask us. For a detailed manual just click here."
 let linkTextWithColor = "click here"

 let range = (text as NSString).rangeOfString(linkTextWithColor)

 let attributedString = NSMutableAttributedString(string:text)
 attributedString.addAttribute(NSForegroundColorAttributeName, value: UIColor.redColor() , range: range)

 self.helpText.attributedText = attributedString

self.helpText是一个UILabel出路.

在之前的帖子中已经给出了答案,但我有不同的方法

Swift 3x:

var myMutableString = NSMutableAttributedString()

myMutableString = NSMutableAttributedString(string: "Your full label textString")

myMutableString.setAttributes([NSFontAttributeName : UIFont(name: "HelveticaNeue-Light", size: CGFloat(17.0))!
        , NSForegroundColorAttributeName : UIColor(red: 232 / 255.0, green: 117 / 255.0, blue: 40 / 255.0, alpha: 1.0)], range: NSRange(location:12,length:8)) // What ever range you want to give

yourLabel.attributedText = myMutableString

希望这对任何人都有帮助!

我看到你在某种程度上回答了这个问题,但是在不使用正则表达式回答标题问题的情况下提供一种更简洁的方法:

要更改文本长度的颜色,您需要知道字符串中有颜色字符的开始和结束索引,例如

var main_string = "Hello World"
var string_to_color = "World"

var range = (main_string as NSString).rangeOfString(string_to_color)

然后转换为属性字符串并使用NSForegroundColorAttributeName的'add attribute':

var attributedString = NSMutableAttributedString(string:main_string)
attributedString.addAttribute(NSForegroundColorAttributeName, value: UIColor.redColor() , range: range)

您可以设置的其他标准属性列表可以在Apple的文档中找到

Swift 4.2和Swift 5对字符串的部分进行着色。

在扩展String时使用NSMutableAttributedString的一种非常简单的方法。这也可以用于给整个字符串中的多个单词上色。

为扩展名添加新文件，文件->新建->新文件，名称为ex。“ NSAttributedString + TextColouring”并添加代码

import UIKit

extension String {
    func attributedStringWithColor(_ strings: [String], color: UIColor, characterSpacing: UInt? = nil) -> NSAttributedString {
        let attributedString = NSMutableAttributedString(string: self)
        for string in strings {
            let range = (self as NSString).range(of: string)
            attributedString.addAttribute(NSAttributedString.Key.foregroundColor, value: color, range: range)
        }

        guard let characterSpacing = characterSpacing else {return attributedString}

        attributedString.addAttribute(NSAttributedString.Key.kern, value: characterSpacing, range: NSRange(location: 0, length: attributedString.length))

        return attributedString
    }
}

现在，您可以在所需的任何视图控制器上全局使用：

let attributedWithTextColor: NSAttributedString = "Doc, welcome back :)".attributedStringWithColor(["Doc", "back"], color: UIColor.black)

myLabel.attributedText = attributedWithTextColor

Swift 4.1

NSAttributedStringKey.foregroundColor

例如,如果要更改NavBar中的字体:

self.navigationController?.navigationBar.titleTextAttributes = [ NSAttributedStringKey.font: UIFont.systemFont(ofSize: 22), NSAttributedStringKey.foregroundColor: UIColor.white]

您可以使用此扩展程序，我将对其进行测试

迅捷4.2

import Foundation
import UIKit

extension NSMutableAttributedString {

    convenience init (fullString: String, fullStringColor: UIColor, subString: String, subStringColor: UIColor) {
           let rangeOfSubString = (fullString as NSString).range(of: subString)
           let rangeOfFullString = NSRange(location: 0, length: fullString.count)//fullString.range(of: fullString)
           let attributedString = NSMutableAttributedString(string:fullString)
           attributedString.addAttribute(NSAttributedStringKey.foregroundColor, value: fullStringColor, range: rangeOfFullString)
           attributedString.addAttribute(NSAttributedStringKey.foregroundColor, value: subStringColor, range: rangeOfSubString)

           self.init(attributedString: attributedString)
   }

}