ios - 哪个 NSCharacterSet 描述了在 tel : URL? 中有效的字符

Question

接受 String 的 NSURL 初始化器是可失败的，文档说:

If the URL string was malformed, returns nil.

尝试使用 NSURL(string: "tel://+49 00 00 00 00 00") 构建 URL 返回 nil。

stringByAddingPercentEscapesUsingEncoding(_:) 和 friend 在 iOS 9 中被弃用，取而代之的是 stringByAddingPercentEncodingWithAllowedCharacters(_:)，它采用 NSCharacterSet。哪个 NSCharacterSet 描述了 tel: URL 中有效的字符？

没有

• URLFragmentAllowedCharacterSet()
• URLHostAllowedCharacterSet()
• URLPasswordAllowedCharacterSet()
• URLPathAllowedCharacterSet()
• URLQueryAllowedCharacterSet()
• URLUserAllowedCharacterSet()

...似乎是相关的

Answer 1

您可以使用 NSDataDetector 类从字符串中 grep 电话号码。下一步从检测到的数字中删除所有不必要的字符并创建 NSURL。

  func getPhoneNumber(string: String) -> String? {
        if let detector = try? NSDataDetector(types: NSTextCheckingType.PhoneNumber.rawValue) {
            let matches = detector.matchesInString(string, options: [], range: NSMakeRange(0, string.characters.count))

            if let string = matches.flatMap({ return $0.phoneNumber}).first {
                let number = convertStringToNumber(string)
                return number
            }
        }


        return nil
    }

    func convertStringToNumber(var str: String) -> String {
        let set = NSMutableCharacterSet()
        set.formUnionWithCharacterSet(NSCharacterSet.whitespaceCharacterSet())
        set.formUnionWithCharacterSet(NSCharacterSet.symbolCharacterSet())
        set.formUnionWithCharacterSet(NSCharacterSet.punctuationCharacterSet())

        str = str.componentsSeparatedByCharactersInSet(set).reduce(String(), combine: +)

        return str
    }

示例:

 let possibleNumber = "+49 00 00 00 00 00"

 if let number = getPhoneNumber(possibleNumber), let url = NSURL(string: "tel://\(number)") {
     print(url.absoluteString)
 }