哪個NSCharacterSet描述在tel：URL中有效的字符？

Question

的NSURL初始化，需要一個String是failable和文檔說：

如果URL字符串格式錯誤，返回零。

試圖構造一個帶有NSURL(string: "tel://+49 00 00 00 00 00")的URL返回nil。

stringByAddingPercentEscapesUsingEncoding(_:)和朋友在iOS版9贊成stringByAddingPercentEncodingWithAllowedCharacters(_:)，這需要一個NSCharacterSet棄用。哪個NSCharacterSet描述了在tel: URL中有效的字符？

無的

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

...似乎是相關

Answer 1

可以NSDataDetector類從字符串grep的電話號碼。下一步刪除檢測到的數字中的所有不必要的字符並創建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 
    } 

例子：

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

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