许多应用程序都有文本,文本中是圆角矩形的web超链接,当我点击它们时,UIWebView就会打开。让我困惑的是,他们经常有自定义链接,例如,如果单词以#开头,它也是可点击的,应用程序通过打开另一个视图来响应。我该怎么做呢?是否可以用UILabel或者我需要UITextView或者其他什么?


当前回答

翻译@samwize的扩展到Swift 4:

extension UITapGestureRecognizer {
    func didTapAttributedTextInLabel(label: UILabel, inRange targetRange: NSRange) -> Bool {
        guard let attrString = label.attributedText else {
            return false
        }

        let layoutManager = NSLayoutManager()
        let textContainer = NSTextContainer(size: .zero)
        let textStorage = NSTextStorage(attributedString: attrString)

        layoutManager.addTextContainer(textContainer)
        textStorage.addLayoutManager(layoutManager)

        textContainer.lineFragmentPadding = 0
        textContainer.lineBreakMode = label.lineBreakMode
        textContainer.maximumNumberOfLines = label.numberOfLines
        let labelSize = label.bounds.size
        textContainer.size = labelSize

        let locationOfTouchInLabel = self.location(in: label)
        let textBoundingBox = layoutManager.usedRect(for: textContainer)
        let textContainerOffset = CGPoint(x: (labelSize.width - textBoundingBox.size.width) * 0.5 - textBoundingBox.origin.x, y: (labelSize.height - textBoundingBox.size.height) * 0.5 - textBoundingBox.origin.y)
        let locationOfTouchInTextContainer = CGPoint(x: locationOfTouchInLabel.x - textContainerOffset.x, y: locationOfTouchInLabel.y - textContainerOffset.y)
        let indexOfCharacter = layoutManager.characterIndex(for: locationOfTouchInTextContainer, in: textContainer, fractionOfDistanceBetweenInsertionPoints: nil)
        return NSLocationInRange(indexOfCharacter, targetRange)
    }
}

要设置识别器(一旦你给文本和东西上色):

lblTermsOfUse.isUserInteractionEnabled = true
lblTermsOfUse.addGestureRecognizer(UITapGestureRecognizer(target: self, action: #selector(handleTapOnLabel(_:))))

...然后是手势识别器:

@objc func handleTapOnLabel(_ recognizer: UITapGestureRecognizer) {
    guard let text = lblAgreeToTerms.attributedText?.string else {
        return
    }

    if let range = text.range(of: NSLocalizedString("_onboarding_terms", comment: "terms")),
        recognizer.didTapAttributedTextInLabel(label: lblAgreeToTerms, inRange: NSRange(range, in: text)) {
        goToTermsAndConditions()
    } else if let range = text.range(of: NSLocalizedString("_onboarding_privacy", comment: "privacy")),
        recognizer.didTapAttributedTextInLabel(label: lblAgreeToTerms, inRange: NSRange(range, in: text)) {
        goToPrivacyPolicy()
    }
}

其他回答

我强烈建议使用自动检测文本中的url并将其转换为链接的库。 试一试:

TTTAttributedLabel (pod) ZSWTappableLabel (under).

两者都得到了麻省理工学院的许可。

我创建了一个名为ResponsiveLabel的UILabel子类,它是基于ios7中引入的textkit API。它使用了NAlexN建议的相同方法。它提供了在文本中指定搜索模式的灵活性。可以指定应用于这些模式的样式,以及在敲击模式时要执行的操作。

//Detects email in text

 NSString *emailRegexString = @"[A-Z0-9._%+-]+@[A-Z0-9.-]+\\.[A-Z]{2,4}";
 NSError *error;
 NSRegularExpression *regex = [[NSRegularExpression alloc]initWithPattern:emailRegexString options:0 error:&error];
 PatternDescriptor *descriptor = [[PatternDescriptor alloc]initWithRegex:regex withSearchType:PatternSearchTypeAll withPatternAttributes:@{NSForegroundColorAttributeName:[UIColor redColor]}];
 [self.customLabel enablePatternDetection:descriptor];

如果你想让一个字符串可点击,你可以这样做。这段代码将属性应用到字符串“text”的每个出现处。

PatternTapResponder tapResponder = ^(NSString *string) {
    NSLog(@"tapped = %@",string);
};

[self.customLabel enableStringDetection:@"text" withAttributes:@{NSForegroundColorAttributeName:[UIColor redColor],
                                                                 RLTapResponderAttributeName: tapResponder}];

UITextView支持OS3.0中的数据检测器,而UILabel不支持。

如果你在UITextView上启用了数据检测器,并且你的文本包含url、电话号码等,它们将以链接的形式出现。

基于Charles Gamble的答案,这是我使用的(我删除了一些让我困惑并给我错误索引的行):

- (BOOL)didTapAttributedTextInLabel:(UILabel *)label inRange:(NSRange)targetRange TapGesture:(UIGestureRecognizer*) gesture{
    NSParameterAssert(label != nil);

    // create instances of NSLayoutManager, NSTextContainer and NSTextStorage
    NSLayoutManager *layoutManager = [[NSLayoutManager alloc] init];
    NSTextStorage *textStorage = [[NSTextStorage alloc] initWithAttributedString:label.attributedText];

    // configure layoutManager and textStorage
    [textStorage addLayoutManager:layoutManager];

    // configure textContainer for the label
    NSTextContainer *textContainer = [[NSTextContainer alloc] initWithSize:CGSizeMake(label.frame.size.width, label.frame.size.height)];

    textContainer.lineFragmentPadding = 0.0;
    textContainer.lineBreakMode = label.lineBreakMode;
    textContainer.maximumNumberOfLines = label.numberOfLines;

    // find the tapped character location and compare it to the specified range
    CGPoint locationOfTouchInLabel = [gesture locationInView:label];
    [layoutManager addTextContainer:textContainer]; //(move here, not sure it that matter that calling this line after textContainer is set

    NSInteger indexOfCharacter = [layoutManager characterIndexForPoint:locationOfTouchInLabel
                                                           inTextContainer:textContainer
                                  fractionOfDistanceBetweenInsertionPoints:nil];
    if (NSLocationInRange(indexOfCharacter, targetRange)) {
        return YES;
    } else {
        return NO;
    }
}

Drop-in解决方案作为UILabel上的一个类别(这假设你的UILabel使用一个带有NSLinkAttributeName属性的带属性字符串):

@implementation UILabel (Support)

- (BOOL)openTappedLinkAtLocation:(CGPoint)location {
  CGSize labelSize = self.bounds.size;

  NSTextContainer* textContainer = [[NSTextContainer alloc] initWithSize:CGSizeZero];
  textContainer.lineFragmentPadding = 0.0;
  textContainer.lineBreakMode = self.lineBreakMode;
  textContainer.maximumNumberOfLines = self.numberOfLines;
  textContainer.size = labelSize;

  NSLayoutManager* layoutManager = [[NSLayoutManager alloc] init];
  [layoutManager addTextContainer:textContainer];

  NSTextStorage* textStorage = [[NSTextStorage alloc] initWithAttributedString:self.attributedText];
  [textStorage addAttribute:NSFontAttributeName value:self.font range:NSMakeRange(0, textStorage.length)];
  [textStorage addLayoutManager:layoutManager];

  CGRect textBoundingBox = [layoutManager usedRectForTextContainer:textContainer];
  CGPoint textContainerOffset = CGPointMake((labelSize.width - textBoundingBox.size.width) * 0.5 - textBoundingBox.origin.x,
                                            (labelSize.height - textBoundingBox.size.height) * 0.5 - textBoundingBox.origin.y);
  CGPoint locationOfTouchInTextContainer = CGPointMake(location.x - textContainerOffset.x, location.y - textContainerOffset.y);
  NSInteger indexOfCharacter = [layoutManager characterIndexForPoint:locationOfTouchInTextContainer inTextContainer:textContainer fractionOfDistanceBetweenInsertionPoints:nullptr];
  if (indexOfCharacter >= 0) {
    NSURL* url = [textStorage attribute:NSLinkAttributeName atIndex:indexOfCharacter effectiveRange:nullptr];
    if (url) {
      [[UIApplication sharedApplication] openURL:url];
      return YES;
    }
  }
  return NO;
}

@end