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)
    }

}

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。

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

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)

可能的解决方案

Swift提供了distance()来测量开始和结束之间的距离，可以用来创建一个NSRange:

let text = "Long paragraph saying something goes here!"
let textRange = text.startIndex..<text.endIndex
let attributedString = NSMutableAttributedString(string: text)

text.enumerateSubstringsInRange(textRange, options: NSStringEnumerationOptions.ByWords, { (substring, substringRange, enclosingRange, stop) -> () in
    let start = distance(text.startIndex, substringRange.startIndex)
    let length = distance(substringRange.startIndex, substringRange.endIndex)
    let range = NSMakeRange(start, length)

//    println("word: \(substring) - \(d1) to \(d2)")

        if (substring == "saying") {
            attributedString.addAttribute(NSForegroundColorAttributeName, value: NSColor.redColor(), range: range)
        }
})