Question

我想要完成的工作如下。我有一个NSString，其中一个句子在感知中有一个URL。我需要能够获取NSString中任何句子中显示的URL，例如：

假设我有这个NSString

NSString *someString = @"This is a sample of a http://abc.com/efg.php?EFAei687e3EsA sentence with a URL within it.";

我需要能够从该NSString中提取http://abc.com/efg.php?EFAei687e3EsA。这个NSString不是静态的，并且将改变结构，并且url不一定在句子的同一位置。我试着调查三个代码，但对我来说没有意义。怎么办呢？谢谢你的帮助。

Answer 1

使用NSDataDetector：

NSString *string = @"This is a sample of a http://abc.com/efg.php?EFAei687e3EsA sentence with a URL within it.";
NSDataDetector *linkDetector = [NSDataDetector dataDetectorWithTypes:NSTextCheckingTypeLink error:nil];
NSArray *matches = [linkDetector matchesInString:string options:0 range:NSMakeRange(0, [string length])];
for (NSTextCheckingResult *match in matches) {
  if ([match resultType] == NSTextCheckingTypeLink) {
    NSURL *url = [match URL];
    NSLog(@"found URL: %@", url);
  }
}

这样您就不必依赖不可靠的正则表达式，并且当Apple升级其链接检测代码时，您可以免费获得这些改进。

Answer 2

编辑：我打算在这里走出去，说你应该像Dave提到的那样使用NSDataDetector。比正则表达式更容易出错。

看看regular expressions。您可以使用NSRegularExpression类构建一个简单的URL来提取URL（仅适用于iPhone，但由于这是您的目标，您可以），或者在线找到一个可以使用的URL。有关使用该课程的教程，请参阅here。

您想要的代码基本上是这样的（使用John Gruber的super URL regex）：

NSRegularExpression *expression = [NSRegularExpression regularExpressionWithPattern:@"(?i)\\b((?:[a-z][\\w-]+:(?:/{1,3}|[a-z0-9%])|www\\d{0,3}[.]|[a-z0-9.\\-]+[.][a-z]{2,4}/)(?:[^\\s()<>]+|\\(([^\\s()<>]+|(\\([^\\s()<>]+\\)))*\\))+(?:\\(([^\\s()<>]+|(\\([^\\s()<>]+\\)))*\\)|[^\\s`!()\\[\\]{};:'\".,<>?«»“”‘’]))" options:NSRegularExpressionCaseInsensitive error:NULL];
NSString *someString = @"This is a sample of a http://abc.com/efg.php?EFAei687e3EsA sentence with a URL within it.";
NSString *match = [someString substringWithRange:[expression rangeOfFirstMatchInString:someString options:NSMatchingCompleted range:NSMakeRange(0, [someString length])]];
NSLog(@"%@", match); // Correctly prints 'http://abc.com/efg.php?EFAei687e3EsA'

这将提取任何字符串中的第一个URL（当然，这不会进行错误检查，因此如果字符串确实不包含任何URL，则它将无效，但请查看NSRegularExpression上课了解如何绕过它。

Answer 3

像这样使用：

NSError *error = nil;
NSDataDetector *detector = [NSDataDetector dataDetectorWithTypes:NSTextCheckingTypeLink
                                                           error:&error];

[detector enumerateMatchesInString:someString
                           options:0
                             range:NSMakeRange(0, someString.length)
                        usingBlock:^(NSTextCheckingResult *result, NSMatchingFlags flags, BOOL *stop)
 {
     if (result.resultType == NSTextCheckingTypeLink)
     {
         NSString *str = [NSString stringWithFormat:@"%@",result.URL];
         NSLOG(%@,str);

     }
 }];

这将逐个输出someString中的所有链接

Answer 4

使用此

NSURL *url;
    NSMutableArray *listItems = [[someString componentsSeparatedByString:@" "] mutableCopy];

for(int i=0;i<[listItems count];i++)
{
    NSString *str=[listItems objectAtIndex:i];
      if ([str rangeOfString:@"http://"].location == NSNotFound)
          NSLog(@"Not url");
      else 
        url=[NSURL URLWithString:str];  

}

Answer 5

你需要两件事：

将正则表达式添加到NSString（即RegexKit）
Matching Regex for URLS。

的问候，

Answer 6

有趣的是你提到了three20，这是我第一次去寻找答案。这是来自three20的方法：

- (void)parseURLs:(NSString*)string {
    NSInteger index = 0;
    while (index < string.length) {
        NSRange searchRange = NSMakeRange(index, string.length - index);
        NSRange startRange = [string rangeOfString:@"http://" options:NSCaseInsensitiveSearch
                             range:searchRange];
        if (startRange.location == NSNotFound) {
            NSString* text = [string substringWithRange:searchRange];
            TTStyledTextNode* node = [[[TTStyledTextNode alloc] initWithText:text] autorelease];
            [self addNode:node];
            break;
        } else {
            NSRange beforeRange = NSMakeRange(searchRange.location, startRange.location - searchRange.location);
            if (beforeRange.length) {
                NSString* text = [string substringWithRange:beforeRange];
                TTStyledTextNode* node = [[[TTStyledTextNode alloc] initWithText:text] autorelease];
                [self addNode:node];
            }

            NSRange searchRange = NSMakeRange(startRange.location, string.length - startRange.location);
            NSRange endRange = [string rangeOfString:@" " options:NSCaseInsensitiveSearch
                             range:searchRange];
            if (endRange.location == NSNotFound) {
                NSString* URL = [string substringWithRange:searchRange];
                TTStyledLinkNode* node = [[[TTStyledLinkNode alloc] initWithText:URL] autorelease];
                node.URL = URL;
                [self addNode:node];
                break;
            } else {
                NSRange URLRange = NSMakeRange(startRange.location,
                                         endRange.location - startRange.location);
                NSString* URL = [string substringWithRange:URLRange];
                TTStyledLinkNode* node = [[[TTStyledLinkNode alloc] initWithText:URL] autorelease];
                node.URL = URL;
                [self addNode:node];
                index = endRange.location;
            }
        }
    }
}

每次在[self addNode:node];部分之后if {{1}}，它都会添加找到的网址。这应该让你开始！希望这可以帮助。：）

Answer 7

斯威夫特2：

let input = "This is a test with the URL https://www.hackingwithswift.com to be detected."
let detector = try! NSDataDetector(types: NSTextCheckingType.Link.rawValue)
let matches = detector.matchesInString(input, options: [], range: NSMakeRange(0, input.characters.count))

for match in matches {
    let url = (input as NSString).substringWithRange(match.range)
    print(url)
}

Source

Answer 8

使用Swift 2.2 - NSDataDetector

let string = "here is the link www.google.com"
let types: NSTextCheckingType = [ .Link]
let detector = try? NSDataDetector(types: types.rawValue)
detector?.enumerateMatchesInString(string, options: [], range: NSMakeRange(0, (string as NSString).length)) { (result, flags, _) in
    if(result?.URL != nil){
        print(result?.URL)
    }
}

Answer 9

Swift 4.x
Xcode 12.x

let string = "This is a test with the URL https://www.hackingwithswift.com to be detected. www.example.com"
let types: NSTextCheckingResult.CheckingType = [ .link]
let detector = try? NSDataDetector(types: types.rawValue)
detector?.enumerateMatches(in: string, options: [], range: NSMakeRange(0, (string as NSString).length)) { (result, flags, _) in
    if(result?.url != nil){
        print(result?.url)
    }
}

如何从NSString中的句子中提取URL？

9 个答案: