在我正在开发的iPhone应用程序中，存在一个可以输入URL的设置，由于格式和功能，此URL需要在线和离线进行验证。

到目前为止，我还没有找到任何方法来验证url，所以问题是；

如何在线和离线验证iPhone（Objective-C）上的URL输入？

由于这篇文章，您可以避免使用RegexKit。这是我的解决方案（适用于iOS> 3.0的iPhone开发）：

- (BOOL) validateUrl: (NSString *) candidate {
    NSString *urlRegEx =
    @"(http|https)://((\\w)*|([0-9]*)|([-|_])*)+([\\.|/]((\\w)*|([0-9]*)|([-|_])*))+";
    NSPredicate *urlTest = [NSPredicate predicateWithFormat:@"SELF MATCHES %@", urlRegEx]; 
    return [urlTest evaluateWithObject:candidate];
}

如果您想签入Swift我的解决方案如下：

 func isValidUrl(url: String) -> Bool {
        let urlRegEx = "^(https?://)?(www\\.)?([-a-z0-9]{1,63}\\.)*?[a-z0-9][-a-z0-9]{0,61}[a-z0-9]\\.[a-z]{2,6}(/[-\\w@\\+\\.~#\\?&/=%]*)?$"
        let urlTest = NSPredicate(format:"SELF MATCHES %@", urlRegEx)
        let result = urlTest.evaluate(with: url)
        return result
    }

为什么不仅仅依靠Foundation.framework呢？

这样就可以了，不需要RegexKit：

NSURL *candidateURL = [NSURL URLWithString:candidate];
// WARNING > "test" is an URL according to RFCs, being just a path
// so you still should check scheme and all other NSURL attributes you need
if (candidateURL && candidateURL.scheme && candidateURL.host) {
  // candidate is a well-formed url with:
  //  - a scheme (like http://)
  //  - a host (like stackoverflow.com)
}

根据Apple文档：

URLWithString：创建并返回使用提供的字符串初始化的NSURL对象。

+ (id)URLWithString:(NSString *)URLString

参量

URLString：用于初始化NSURL对象的字符串。必须符合RFC2396。此方法根据RFC 1738和1808解析URLString。

返回值

使用URLString初始化的NSURL对象。如果字符串格式错误，则返回nil。

不用编写自己的正则表达式，而要依靠Apple的正则表达式。我一直在NSString使用NSDataDetector用于测试字符串中链接是否存在的类别。如果找到的链接范围NSDataDetector等于整个字符串的长度，则它是有效的URL。

- (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;
}

我的Swift解决方案：

func validateUrl (stringURL : NSString) -> Bool {

    var urlRegEx = "((https|http)://)((\\w|-)+)(([.]|[/])((\\w|-)+))+"
    let predicate = NSPredicate(format:"SELF MATCHES %@", argumentArray:[urlRegEx])
    var urlTest = NSPredicate.predicateWithSubstitutionVariables(predicate)

    return predicate.evaluateWithObject(stringURL)
}

测试：

var boolean1 = validateUrl("http.s://www.gmail.com")
var boolean2 = validateUrl("https:.//gmailcom")
var boolean3 = validateUrl("https://gmail.me.")
var boolean4 = validateUrl("https://www.gmail.me.com.com.com.com")
var boolean6 = validateUrl("http:/./ww-w.wowone.com")
var boolean7 = validateUrl("http://.www.wowone")
var boolean8 = validateUrl("http://www.wow-one.com")
var boolean9 = validateUrl("http://www.wow_one.com")
var boolean10 = validateUrl("http://.")
var boolean11 = validateUrl("http://")
var boolean12 = validateUrl("http://k")

结果：

false
false
false
true
false
false
true
true
false
false
false

用这个-

NSString *urlRegEx = @"http(s)?://([\\w-]+\\.)+[\\w-]+(/[\\w- ./?%&=]*)?";

我使用RegexKit解决了问题，并构建了一个快速的正则表达式来验证URL；

NSString *regexString = @"(http|https)://((\\w)*|([0-9]*)|([-|_])*)+([\\.|/]((\\w)*|([0-9]*)|([-|_])*))+";
NSString *subjectString = brandLink.text;
NSString *matchedString = [subjectString stringByMatching:regexString];

然后，我检查matchedString是否等于subjectString，如果是这种情况，则URL有效:)

如果我的正则表达式不正确，请纠正我;）

奇怪的是，我在这里没有真正找到一个非常简单的解决方案，但是在处理http/ https链接方面仍然做得不错。

请记住，这不是一个完美的解决方案，但它适用于以下情况。总之，正则表达式将测试URL是否以http://或开头https://，然后检查至少1个字符，然后检查点，然后再次检查至少1个字符。不允许有空格。

+ (BOOL)validateLink:(NSString *)link
{
    NSString *regex = @"(?i)(http|https)(:\\/\\/)([^ .]+)(\\.)([^ \n]+)";
    NSPredicate *predicate = [NSPredicate predicateWithFormat:@"SELF MATCHES %@", regex];
    return [predicate evaluateWithObject:link];
}

针对以下网址测试了VALID：

@"HTTP://FOO.COM",
@"HTTPS://FOO.COM",
@"http://foo.com/blah_blah",
@"http://foo.com/blah_blah/",
@"http://foo.com/blah_blah_(wikipedia)",
@"http://foo.com/blah_blah_(wikipedia)_(again)",
@"http://www.example.com/wpstyle/?p=364",
@"https://www.example.com/foo/?bar=baz&inga=42&quux",
@"http://✪df.ws/123",
@"http://userid:password@example.com:8080",
@"http://userid:password@example.com:8080/",
@"http://userid@example.com",
@"http://userid@example.com/",
@"http://userid@example.com:8080",
@"http://userid@example.com:8080/",
@"http://userid:password@example.com",
@"http://userid:password@example.com/",
@"http://142.42.1.1/",
@"http://142.42.1.1:8080/",
@"http://➡.ws/䨹",
@"http://⌘.ws",
@"http://⌘.ws/",
@"http://foo.com/blah_(wikipedia)#cite-",
@"http://foo.com/blah_(wikipedia)_blah#cite-",
@"http://foo.com/unicode_(✪)_in_parens",
@"http://foo.com/(something)?after=parens",
@"http://☺.damowmow.com/",
@"http://code.google.com/events/#&product=browser",
@"http://j.mp",
@"http://foo.bar/?q=Test%20URL-encoded%20stuff",
@"http://مثال.إختبار",
@"http://例子.测试",
@"http://उदाहरण.परीक्षा",
@"http://-.~_!$&'()*+,;=:%40:80%2f::::::@example.com",
@"http://1337.net",
@"http://a.b-c.de",
@"http://223.255.255.254"

针对以下网址测试了无效：

@"",
@"foo",
@"ftp://foo.com",
@"ftp://foo.com",
@"http://..",
@"http://..",
@"http://../",
@"//",
@"///",
@"http://##/",
@"http://.www.foo.bar./",
@"rdar://1234",
@"http://foo.bar?q=Spaces should be encoded",
@"http:// shouldfail.com",
@":// should fail"

网址来源：https： //mathiasbynens.be/demo/url-regex

你可以使用这个，如果你不想http或者https或www

NSString *urlRegEx = @"^(http(s)?://)?((www)?\.)?[\w]+\.[\w]+";

例

- (void) testUrl:(NSString *)urlString{
    NSLog(@"%@: %@", ([self isValidUrl:urlString] ? @"VALID" : @"INVALID"), urlString);
}

- (void)doTestUrls{
    [self testUrl:@"google"];
    [self testUrl:@"google.de"];
    [self testUrl:@"www.google.de"];
    [self testUrl:@"http://www.google.de"];
    [self testUrl:@"http://google.de"];
}

输出：

INVALID: google
VALID: google.de
VALID: www.google.de
VALID: http://www.google.de
VALID: http://google.de

Lefakir的解决方案有一个问题。他的正则表达式无法与“ http://instagram.com/p/4Mz3dTJ-ra/ ” 匹配。网址组件结合了数字和文字字符。他的正则表达式无法通过此类网址。

这是我的进步。

"(http|https)://((\\w)*|([0-9]*)|([-|_])*)+([\\.|/]((\\w)*|([0-9]*)|([-|_])*)+)+(/)?(\\?.*)?"

我发现最简单的方法是这样的：

- (BOOL)validateUrl: (NSURL *)candidate
{
    NSURLRequest *req = [NSURLRequest requestWithURL:candidate];
    return [NSURLConnection canHandleRequest:req];
}

以下代码可让您找到有效的网址

      NSPredicate *websitePredicate = [NSPredicate predicateWithFormat:@"SELF MATCHES %@",@"^(((((h|H)(t|T){2}(p|P)s?)|((f|F)(t|T)(p|P)))://(w{3}.)?)|(w{3}.))[A-Za-z0-9]+(.[A-Za-z0-9-:;\?#_]+)+"];
     if ([websitePredicate evaluateWithObject:##MY_STRING##])
     {
       printf"Valid"
     }

对于这样的URL

• http://123.com
• https://123.com
• http://www.123.com
• https://www.123.com
• ftp://123.com
• ftp://www.123.com
• www.something.com

批准的答案不正确。我有一个带有“-”的URL，验证失败。

Tweeked Vaibhav支持G +链接的答案：

NSString *urlRegEx = @"http(s)?://([\\w-]+\\.)+[\\w-]+(/[\\w-\\+ ./?%&=]*)?";

在上述解决方案中，某些URL末尾没有/的URL未被检测为正确的URL。因此，这可能会有所帮助。

  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
    }
}

Swift中的URL验证

细节

Xcode 8.2.1，Swift 3

码

枚举URLSchemes：字符串

import Foundation

enum URLSchemes: String {
    case http = "http://", https = "https://", ftp = "ftp://", unknown = "unknown://"

    static func detectScheme(urlString: String) -> URLSchemes {

        if URLSchemes.isSchemeCorrect(urlString: urlString, scheme: .http) {
            return .http
        }
        if URLSchemes.isSchemeCorrect(urlString: urlString, scheme: .https) {
            return .https
        }
        if URLSchemes.isSchemeCorrect(urlString: urlString, scheme: .ftp) {
            return .ftp
        }
        return .unknown
    }

    static func getAllSchemes(separetedBy separator: String) -> String {
        return "\(URLSchemes.http.rawValue)\(separator)\(URLSchemes.https.rawValue)\(separator)\(URLSchemes.ftp.rawValue)"
    }

    private static func isSchemeCorrect(urlString: String, scheme: URLSchemes) -> Bool {
        if urlString.replacingOccurrences(of: scheme.rawValue, with: "") == urlString {
            return false
        }
        return true
    }
}

扩展字符串

import Foundation

extension String {

    var isUrl: Bool {

        // for http://regexr.com checking
        // (?:(?:https?|ftp):\/\/)(?:xn--)?(?:\S+(?::\S*)?@)?(?:(?!10(?:\.\d{1,3}){3})(?!127(?:\.\d{1,3}){3})(?!169\.254(?:\.\d{1,3}){2})(?!192\.168(?:\.\d{1,3}){2})(?!172\.(?:1[6-9]|2\d|3[0-1])(?:\.\d{1,3}){2})(?:[1-9]\d?|1\d\d|2[01]\d|22[0-3])(?:\.(?:1?\d{1,2}|2[0-4]\d|25[0-5])){2}(?:\.(?:[1-9]\d?|1\d\d|2[0-4]\d|25[0-4]))|(?:(?:[a-z\u00a1-\uffff0-9]+-?)*[a-z\u00a1-\uffff0-9]+)(?:\.(?:[a-z\u00a1-\uffff0-9]+-?)*[a-z\u00a1-\uffff0-9]+)*(?:\.(?:[#-z\u00a1-\uffff]{2,})))(?::\d{2,5})?(?:\/[^\s]*)?

        let schemes = URLSchemes.getAllSchemes(separetedBy: "|").replacingOccurrences(of: "://", with: "")
        let regex = "(?:(?:\(schemes)):\\/\\/)(?:xn--)?(?:\\S+(?::\\S*)?@)?(?:(?!10(?:\\.\\d{1,3}){3})(?!127(?:\\.\\d{1,3}){3})(?!169\\.254(?:\\.\\d{1,3}){2})(?!192\\.168(?:\\.\\d{1,3}){2})(?!172\\.(?:1[6-9]|2\\d|3[0-1])(?:\\.\\d{1,3}){2})(?:[1-9]\\d?|1\\d\\d|2[01]\\d|22[0-3])(?:\\.(?:1?\\d{1,2}|2[0-4]\\d|25[0-5])){2}(?:\\.(?:[1-9]\\d?|1\\d\\d|2[0-4]\\d|25[0-4]))|(?:(?:[a-z\\u00a1-\\uffff0-9]+-?)*[a-z\\u00a1-\\uffff0-9]+)(?:\\.(?:[a-z\\u00a1-\\uffff0-9]+-?)*[a-z\\u00a1-\\uffff0-9]+)*(?:\\.(?:[#-z\\u00a1-\\uffff]{2,})))(?::\\d{2,5})?(?:\\/[^\\s]*)?"


        let regularExpression = try! NSRegularExpression(pattern: regex, options: [])
        let range = NSRange(location: 0, length: self.characters.count)
        let matches = regularExpression.matches(in: self, options: [], range: range)
        for match in matches {
            if range.location == match.range.location && range.length == match.range.length {
                return true
            }
        }
        return false
    }

    var toURL: URL? {

        let urlChecker: (String)->(URL?) = { url_string in
            if url_string.isUrl, let url = URL(string: url_string) {
                return url
            }
            return nil
        }

        if !contains(".") {
            return nil
        }

        if let url = urlChecker(self) {
            return url
        }

        let scheme = URLSchemes.detectScheme(urlString: self)
        if scheme == .unknown {
            let newEncodedString = URLSchemes.http.rawValue + self
            if let url = urlChecker(newEncodedString) {
                return url
            }
        }

        return nil
    }
}

用法

 func tests() {

    chekUrl(urlString:"http://example.com")
    chekUrl(urlString:"https://example.com")
    chekUrl(urlString:"http://example.com/dir/file.php?var=moo")
    chekUrl(urlString:"http://xn--h1aehhjhg.xn--d1acj3b")
    chekUrl(urlString:"http://www.example.com/wpstyle/?p=364")
    chekUrl(urlString:"http://-.~_!$&'()*+,;=:%40:80%2f::::::@example.com")
    chekUrl(urlString:"http://example.com")
    chekUrl(urlString:"http://xn--d1acpjx3f.xn--p1ai")
    chekUrl(urlString:"http://xn--74h.damowmow.com/")
    chekUrl(urlString:"ftp://example.com:129/myfiles")
    chekUrl(urlString:"ftp://user:pass@site.com:21/file/dir")
    chekUrl(urlString:"ftp://ftp.example.com:2828/asdah%20asdah.gif")
    chekUrl(urlString:"http://142.42.1.1:8080/")
    chekUrl(urlString:"http://142.42.1.1/")
    chekUrl(urlString:"http://userid:password@example.com:8080")
    chekUrl(urlString:"http://userid@example.com")
    chekUrl(urlString:"http://userid@example.com:8080")
    chekUrl(urlString:"http://foo.com/blah_(wikipedia)#cite-1")
    chekUrl(urlString:"http://foo.com/(something)?after=parens")

    print("\n----------------------------------------------\n")

    chekUrl(urlString:".")
    chekUrl(urlString:" ")
    chekUrl(urlString:"")
    chekUrl(urlString:"-/:;()₽&@.,?!'{}[];'<>+_)(*#^%$")
    chekUrl(urlString:"localhost")
    chekUrl(urlString:"yandex.")
    chekUrl(urlString:"коряга")
    chekUrl(urlString:"http:///a")
    chekUrl(urlString:"ftps://foo.bar/")
    chekUrl(urlString:"rdar://1234")
    chekUrl(urlString:"h://test")
    chekUrl(urlString:":// should fail")
    chekUrl(urlString:"http://-error-.invalid/")
    chekUrl(urlString:"http://.www.example.com/")
}

func chekUrl(urlString: String) {
    var result = ""
    if urlString.isUrl {
        result += "url: "
    } else {
        result += "not url: "
    }
    result += "\"\(urlString)\""
    print(result)
}

结果

目标C

- (BOOL)validateUrlString:(NSString*)urlString
{
    if (!urlString)
    {
        return NO;
    }

    NSDataDetector *linkDetector = [NSDataDetector dataDetectorWithTypes:NSTextCheckingTypeLink error:nil];

    NSRange urlStringRange = NSMakeRange(0, [urlString length]);
    NSMatchingOptions matchingOptions = 0;

    if (1 != [linkDetector numberOfMatchesInString:urlString options:matchingOptions range:urlStringRange])
    {
        return NO;
    }

    NSTextCheckingResult *checkingResult = [linkDetector firstMatchInString:urlString options:matchingOptions range:urlStringRange];

    return checkingResult.resultType == NSTextCheckingTypeLink && NSEqualRanges(checkingResult.range, urlStringRange);
}

希望这可以帮助！

您的意思是要检查用户输入的是URL吗？它可以像正则表达式一样简单，例如检查字符串是否包含www.（这是yahoo messenger检查用户状态是否为链接的方式）
希望对您有所帮助

自私地，我建议使用一个KSURLFormatter实例来验证输入，并将其转换为NSURL可以处理的东西。

我创建了UITextField的继承类，该类可以使用正则表达式字符串处理所有类型的验证。在这种情况下，您只需要依次为他们提供所有正则表达式字符串和要在验证失败时显示的消息即可。您可以查看我的博客以获取更多信息，它确实可以为您提供帮助

http://dhawaldawar.wordpress.com/2014/06/11/uitextfield-validation-ios/

将@Anthony的答案扩展到swift，我编写了一个类别，在String该类别上返回了optional NSURL。返回值是nil如果String不能将其验证为URL。

import Foundation

// A private global detector variable which can be reused.
private let detector = try! NSDataDetector(types: NSTextCheckingType.Link.rawValue)

extension String {
  func URL() -> NSURL? {
    let textRange = NSMakeRange(0, self.characters.count)
    guard let URLResult = detector.firstMatchInString(self, options: [], range: textRange) else {
      return nil
    }

    // This checks that the whole string is the detected URL. In case
    // you don't have such a requirement, you can remove this code
    // and return the URL from URLResult.
    guard NSEqualRanges(URLResult.range, textRange) else {
      return nil
    }

    return NSURL(string: self)
  }
}

func checkValidUrl(_ strUrl: String) -> Bool {
    let urlRegEx: String = "(http|https)://((\\w)*|([0-9]*)|([-|_])*)+([\\.|/]((\\w)*|([0-9]*)|([-|_])*))+"
    let urlTest = NSPredicate(format: "SELF MATCHES %@", urlRegEx)
    return urlTest.evaluate(with: strUrl)
}