如何从使用nsrange的emoj字符串中获取部分内容

Question

我有文本里面有表情符号，我必须使用Nsrange来获取子字符串。

由于表情符号，我没有得到子字符串，我使用下面的代码来查找子字符串，并且当表情符号不存在时它工作正常。快速回答的问题。

    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

不要使用NSRange来获取Swift中的子串。

将NSRange转换为Range<String.Index>有两种便利API，反之亦然

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

例如，用第二个函数替​​换

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])
    }
}