如何使用nsrange从具有emoj的字符串中获取某些部分

Question

我的文字中包含表情符号，我必须使用Nsrange获取子字符串。

由于表情符号，我没有得到子字符串，我正在使用以下代码查找子字符串，当表情符号不存在时，它可以正常工作。 急着想快速的答案。

    extension String {
    //for finding the range
    func nsRanges(ofWord word: String) -> [NSRange] {
        var ranges: [NSRange] = []
        self.enumerateSubstrings(in: startIndex..., options: .byWords) {
            (substring, range, _, _) in

            let subrange = NSRange(range, in: self)

            let othersubstring = self.substring(location: subrange.location, length: word.count + 1)
           if othersubstring != nil{
                if othersubstring!  == word + " " {
                    ranges.append(NSRange(location: subrange.location, length: word.count))

                }
            }
        }
        return ranges
    }
    //for substring *emphasized text*
    func substring(location: Int, length: Int) -> String? {
        guard self.utf16.count >= location + length else {

            return nil
        }
        let start = index(startIndex, offsetBy: location)
        let end = index(startIndex, offsetBy: location + length)
        return substring(with: start..<end)
    }
}

Answer 1

根本不要使用NSRange在Swift中获取子字符串。

有两个便捷的API可以将NSRange转换为Range<String.Index> ，反之亦然

• init?(_ range: NSRange, in string: String)在Range
• NSRange(_ range: Range<String.Index>, in string: StringProtocol)在NSRange

例如，将第二个功能替换为

extension String {

    func substring(location: Int, length: Int) -> String? {
        let nsRange = NSRange(location: location, length: length)
        guard let range = Range(nsRange, in: self) else { return nil }
        return String(self[range])
    }
}