哪个NSCharacterSet描述在tel: URL中有效的字符？

Question

接受一个NSURL的String初始化程序是可失败的，文档中说：

如果URL字符串格式错误，则返回零。

试图使用NSURL(string: "tel://+49 00 00 00 00 00")构造URL返回为零。

stringByAddingPercentEscapesUsingEncoding(_:)和朋友们在iOS 9中反对stringByAddingPercentEncodingWithAllowedCharacters(_:)，因为stringByAddingPercentEncodingWithAllowedCharacters(_:)需要一个NSCharacterSet。哪个NSCharacterSet描述了tel: URL中有效的字符？

都不是

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

..。似乎是相关的

Answer 1

您可以将NSDataDetector类从字符串转到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)
 }