用于 Swift 的 NSNotFound

Posted 2023-03-16

【中文标题】用于 Swift 的 NSNotFound

【英文标题】：NSNotFound for Swift

【发布时间】：2015-09-22 01:30:42

【问题描述】：

我通过Antony 找到了这个用于验证 URL 的解决方案。

- (BOOL)isValidURL 
    NSUInteger length = [self length];
    // Empty strings should return NO
    if (length > 0) 
       NSError *error = nil;
       NSDataDetector *dataDetector = [NSDataDetector dataDetectorWithTypes:NSTextCheckingTypeLink error:&error];
       if (dataDetector && !error) 
          NSRange range = NSMakeRange(0, length);
          NSRange notFoundRange = (NSRange)NSNotFound, 0;
          NSRange linkRange = [dataDetector rangeOfFirstMatchInString:self options:0 range:range];
          if (!NSEqualRanges(notFoundRange, linkRange) && NSEqualRanges(range, linkRange)) 
             return YES;
          
       
       else 
          NSLog(@"Could not create link data detector: %@ %@", [error localizedDescription], [error userInfo]);
       
    
    return NO;

我想尝试一下，但我正在快速编写代码。 这是我目前所拥有的。

extension String
    func isValidURL() -> Bool
         let length:Int = self.characters.count
         var err:NSError? = nil
         let dataDetector:NSDataDetector?
         do
             dataDetector = try NSDataDetector(types: NSTextCheckingType.Link.rawValue)
         catch
             err = error as? NSError
         
         if dataDetector != nil && err != nil
             let range = NSMakeRange(0, length)
             let notFoundRange = (NSRange) NSNotFound, 0  //How do I format this for swift?
             let linkRange = dataDetector?.rangeOfFirstMatchInString(self, options: 0, range: range)
             if !NSEqualRanges(notFoundRange, linkRange) && NSEqualRanges(range, linkRange)
                 return true
             
         else
            print("Could not create link data detector: \(err?.localizedDescription): \(err?.userInfo)")
         

         return false
     
 

绊脚石是 NSNotFound。据我所知，这就是 swift 选项的用途。如何格式化该行？

【参考方案1】：

这只是 C 中结构的 aggregate initialization 语法。您可以改用 NSRange 初始化程序：

let notFoundRange = NSRange(location: NSNotFound, length: 0)

或者，也许更简单：

if linkRange.location != NSNotFound  ...

【参考方案2】：

对于那些对这里感兴趣的人来说，使用 jtbandes 答案在 swift 中工作的相同功能。我已经在一堆 URL 上试过了。看起来效果不错..

extension String
    func isValidURL() -> Bool
        let length:Int = self.characters.count
        var err:NSError?
        var dataDetector:NSDataDetector? = NSDataDetector()
        do
            dataDetector = try NSDataDetector(types: NSTextCheckingType.Link.rawValue)
        catch
            err = error as NSError
        
        if dataDetector != nil
            let range = NSMakeRange(0, length)
            let notFoundRange = NSRange(location: NSNotFound, length: 0)
            let linkRange = dataDetector?.rangeOfFirstMatchInString(self, options: NSMatchingOptions.init(rawValue: 0), range: range)
            if !NSEqualRanges(notFoundRange, linkRange!) && NSEqualRanges(range, linkRange!)
                return true
            
        else
            print("Could not create link data detector: \(err?.localizedDescription): \(err?.userInfo)")
        

        return false