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)
    }

}

let text:String = "Hello Friend"

let searchRange:NSRange = NSRange(location:0,length: text.characters.count)

let range:Range`<Int`> = Range`<Int`>.init(start: searchRange.location, end: searchRange.length)

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

答案很好，但是使用Swift 4你可以简化你的代码:

let text = "Test string"
let substring = "string"

let substringRange = text.range(of: substring)!
let nsRange = NSRange(substringRange, in: text)

小心，因为range函数必须被展开。

斯威夫特4

我认为有两种方法。

1. NSRange(范围，在:)

2. NSRange(location:， length:)

示例代码:

let attributedString = NSMutableAttributedString(string: "Sample Text 12345", attributes: [.font : UIFont.systemFont(ofSize: 15.0)])

// NSRange(range, in: )
if let range = attributedString.string.range(of: "Sample")  {
    attributedString.addAttribute(.foregroundColor, value: UIColor.orange, range: NSRange(range, in: attributedString.string))
}

// NSRange(location: , length: )
if let range = attributedString.string.range(of: "12345") {
    attributedString.addAttribute(.foregroundColor, value: UIColor.green, range: NSRange(location: range.lowerBound.encodedOffset, length: range.upperBound.encodedOffset - range.lowerBound.encodedOffset))
}

屏幕截图:

对我来说，这非常有效:

let font = UIFont.systemFont(ofSize: 12, weight: .medium)
let text = "text"
let attString = NSMutableAttributedString(string: "exemple text :)")

attString.addAttributes([.font: font], range:(attString.string as NSString).range(of: text))

label.attributedText = attString