对于你描述的这种情况，我发现这个方法很有效。它相对简短而甜蜜:

 let attributedString = NSMutableAttributedString(string: "follow the yellow brick road") //can essentially come from a textField.text as well (will need to unwrap though)
 let text = "follow the yellow brick road"
 let str = NSString(string: text) 
 let theRange = str.rangeOfString("yellow")
 attributedString.addAttribute(NSForegroundColorAttributeName, value: UIColor.yellowColor(), range: theRange)

Swift 3扩展变体，保留现有属性。

extension UILabel {
  func setLineHeight(lineHeight: CGFloat) {
    guard self.text != nil && self.attributedText != nil else { return }
    var attributedString = NSMutableAttributedString()

    if let attributedText = self.attributedText {
      attributedString = NSMutableAttributedString(attributedString: attributedText)
    } else if let text = self.text {
      attributedString = NSMutableAttributedString(string: text)
    }

    let style = NSMutableParagraphStyle()
    style.lineSpacing = lineHeight
    style.alignment = self.textAlignment
    let str = NSString(string: attributedString.string)

    attributedString.addAttribute(NSParagraphStyleAttributeName,
                                  value: style,
                                  range: str.range(of: str as String))
    self.attributedText = attributedString
  }
}

func formatAttributedStringWithHighlights(text: String, highlightedSubString: String?, formattingAttributes: [String: AnyObject]) -> NSAttributedString {
    let mutableString = NSMutableAttributedString(string: text)

    let text = text as NSString         // convert to NSString be we need NSRange
    if let highlightedSubString = highlightedSubString {
        let highlightedSubStringRange = text.rangeOfString(highlightedSubString) // find first occurence
        if highlightedSubStringRange.length > 0 {       // check for not found
            mutableString.setAttributes(formattingAttributes, range: highlightedSubStringRange)
        }
    }

    return mutableString
}

我的解决方案是一个字符串扩展，首先获得快速范围，然后获得从字符串的开始到子字符串的开始和结束的距离。

然后使用这些值计算子字符串的开始和长度。然后我们可以将这些值应用到NSMakeRange构造函数。

这个解决方案适用于由多个单词组成的子字符串，这里使用enumerateSubstrings的许多解决方案让我失望。

extension String {

    func NSRange(of substring: String) -> NSRange? {
        // Get the swift range 
        guard let range = range(of: substring) else { return nil }

        // Get the distance to the start of the substring
        let start = distance(from: startIndex, to: range.lowerBound) as Int
        //Get the distance to the end of the substring
        let end = distance(from: startIndex, to: range.upperBound) as Int

        //length = endOfSubstring - startOfSubstring
        //start = startOfSubstring
        return NSMakeRange(start, end - start)
    }

}

我喜欢Swift语言，但是使用NSAttributedString与Swift Range不兼容已经让我头疼了太长时间。因此，为了解决所有这些问题，我设计了以下方法来返回一个NSMutableAttributedString，用你的颜色设置高亮的单词。

这对表情符号不起作用。如果需要，可以修改。

extension String {
    func getRanges(of string: String) -> [NSRange] {
        var ranges:[NSRange] = []
        if contains(string) {
            let words = self.components(separatedBy: " ")
            var position:Int = 0
            for word in words {
                if word.lowercased() == string.lowercased() {
                    let startIndex = position
                    let endIndex = word.characters.count
                    let range = NSMakeRange(startIndex, endIndex)
                    ranges.append(range)
                }
                position += (word.characters.count + 1) // +1 for space
            }
        }
        return ranges
    }
    func highlight(_ words: [String], this color: UIColor) -> NSMutableAttributedString {
        let attributedString = NSMutableAttributedString(string: self)
        for word in words {
            let ranges = getRanges(of: word)
            for range in ranges {
                attributedString.addAttributes([NSForegroundColorAttributeName: color], range: range)
            }
        }
        return attributedString
    }
}

用法:

// The strings you're interested in
let string = "The dog ran after the cat"
let words = ["the", "ran"]

// Highlight words and get back attributed string
let attributedString = string.highlight(words, this: .yellow)

// Set attributed string
label.attributedText = attributedString

对于你描述的这种情况，我发现这个方法很有效。它相对简短而甜蜜:

 let attributedString = NSMutableAttributedString(string: "follow the yellow brick road") //can essentially come from a textField.text as well (will need to unwrap though)
 let text = "follow the yellow brick road"
 let str = NSString(string: text) 
 let theRange = str.rangeOfString("yellow")
 attributedString.addAttribute(NSForegroundColorAttributeName, value: UIColor.yellowColor(), range: theRange)