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

我正在扩展@NAlexN原始的详细解决方案,与@zekel优秀的UITapGestureRecognizer扩展,并在Swift中提供。

Extending UITapGestureRecognizer

extension UITapGestureRecognizer {

    func didTapAttributedTextInLabel(label: UILabel, inRange targetRange: NSRange) -> Bool {
        // Create instances of NSLayoutManager, NSTextContainer and NSTextStorage
        let layoutManager = NSLayoutManager()
        let textContainer = NSTextContainer(size: CGSize.zero)
        let textStorage = NSTextStorage(attributedString: label.attributedText!)

        // Configure layoutManager and textStorage
        layoutManager.addTextContainer(textContainer)
        textStorage.addLayoutManager(layoutManager)

        // Configure textContainer
        textContainer.lineFragmentPadding = 0.0
        textContainer.lineBreakMode = label.lineBreakMode
        textContainer.maximumNumberOfLines = label.numberOfLines
        let labelSize = label.bounds.size
        textContainer.size = labelSize

        // Find the tapped character location and compare it to the specified range
        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)
    }

}

使用

设置UIGestureRecognizer发送动作到tapLabel:,你可以检测目标范围是否在myLabel上被点击。

@IBAction func tapLabel(gesture: UITapGestureRecognizer) {
    if gesture.didTapAttributedTextInLabel(myLabel, inRange: targetRange1) {
        print("Tapped targetRange1")
    } else if gesture.didTapAttributedTextInLabel(myLabel, inRange: targetRange2) {
        print("Tapped targetRange2")
    } else {
        print("Tapped none")
    }
}

重要提示:UILabel换行模式必须设置为按word/char换行。以某种方式,只有当换行模式为其他模式时,NSTextContainer才会假定文本为单行。

其他回答

修改了@timbroder代码,以正确处理swift4.2的多行

extension UITapGestureRecognizer {

    func didTapAttributedTextInLabel(label: UILabel, inRange targetRange: NSRange) -> Bool {
        // Create instances of NSLayoutManager, NSTextContainer and NSTextStorage
        let layoutManager = NSLayoutManager()
        let textContainer = NSTextContainer(size: CGSize.zero)
        let textStorage = NSTextStorage(attributedString: label.attributedText!)

        // Configure layoutManager and textStorage
        layoutManager.addTextContainer(textContainer)
        textStorage.addLayoutManager(layoutManager)

        // Configure textContainer
        textContainer.lineFragmentPadding = 0.0
        textContainer.lineBreakMode = label.lineBreakMode
        textContainer.maximumNumberOfLines = label.numberOfLines
        let labelSize = label.bounds.size
        textContainer.size = labelSize

        // Find the tapped character location and compare it to the specified range
        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: 0 );
        // Adjust for multiple lines of text
        let lineModifier = Int(ceil(locationOfTouchInLabel.y / label.font.lineHeight)) - 1
        let rightMostFirstLinePoint = CGPoint(x: labelSize.width, y: 0)
        let charsPerLine = layoutManager.characterIndex(for: rightMostFirstLinePoint, in: textContainer, fractionOfDistanceBetweenInsertionPoints: nil)

        let indexOfCharacter = layoutManager.characterIndex(for: locationOfTouchInTextContainer, in: textContainer, fractionOfDistanceBetweenInsertionPoints: nil)
        let adjustedRange = indexOfCharacter + (lineModifier * charsPerLine)
        var newTargetRange = targetRange
        if lineModifier > 0 {
            newTargetRange.location = targetRange.location+(lineModifier*Int(ceil(locationOfTouchInLabel.y)))
        }
        return NSLocationInRange(adjustedRange, newTargetRange)
    }
}

UILabel代码

let tapAction = UITapGestureRecognizer(target: self, action: #selector(self.tapLabel(gesture:)))

let quote = "For full details please see our privacy policy and cookie policy."
let attributedString = NSMutableAttributedString(string: quote)

let string1: String = "privacy policy", string2: String = "cookie policy"

// privacy policy
let rangeString1 = quote.range(of: string1)!
let indexString1: Int = quote.distance(from: quote.startIndex, to: rangeString1.lowerBound)
attributedString.addAttributes(
            [.font: <UIfont>,
             .foregroundColor: <UI Color>,
             .underlineStyle: 0, .underlineColor:UIColor.clear
        ], range: NSRange(location: indexString1, length: string1.count));

// cookie policy
let rangeString2 = quote.range(of: string2)!
let indexString2: Int = quote.distance(from: quote.startIndex, to: rangeString2.lowerBound )

attributedString.addAttributes(
            [.font: <UIfont>,
             .foregroundColor: <UI Color>,
             .underlineStyle: 0, .underlineColor:UIColor.clear
        ], range: NSRange(location: indexString2, length: string2.count));

let label = UILabel()
label.frame = CGRect(x: 20, y: 200, width: 375, height: 100)
label.isUserInteractionEnabled = true
label.addGestureRecognizer(tapAction)
label.attributedText = attributedString

编码来识别水龙头

 @objc
  func tapLabel(gesture: UITapGestureRecognizer) {
     if gesture.didTapAttributedTextInLabel(label: <UILabel>, inRange: termsLabelRange {
            print("Terms of service")
     } else if gesture.didTapAttributedTextInLabel(label:<UILabel> inRange: privacyPolicyLabelRange) {
            print("Privacy policy")
     } else {
            print("Tapped none")
     }
    }

一般来说,如果我们想在UILabel显示的文本中有一个可点击的链接,我们需要解决两个独立的任务:

更改部分文本的外观,使其看起来像链接 检测和处理链接上的触摸(打开URL是一个特殊情况)

第一个很简单。从ios6开始,UILabel支持显示带属性的字符串。你所需要做的就是创建并配置一个NSMutableAttributedString实例:

NSMutableAttributedString *attributedString = [[NSMutableAttributedString alloc] initWithString:@"String with a link" attributes:nil];
NSRange linkRange = NSMakeRange(14, 4); // for the word "link" in the string above

NSDictionary *linkAttributes = @{ NSForegroundColorAttributeName : [UIColor colorWithRed:0.05 green:0.4 blue:0.65 alpha:1.0],
                                  NSUnderlineStyleAttributeName : @(NSUnderlineStyleSingle) };
[attributedString setAttributes:linkAttributes range:linkRange];

// Assign attributedText to UILabel
label.attributedText = attributedString;

就是这样!上面的代码使UILabel显示带有链接的String

现在我们应该检测这个链接上的触摸。其思想是捕获UILabel中的所有点击,并确定点击的位置是否足够接近链接。为了捕捉触摸,我们可以在标签中添加点击手势识别器。确保为标签启用userInteraction,默认情况下是关闭的:

label.userInteractionEnabled = YES;
[label addGestureRecognizer:[[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(handleTapOnLabel:)]]; 

现在最复杂的事情是:找出点击是否在显示链接的地方,而不是在标签的任何其他部分。如果我们有单行UILabel,这个任务可以通过硬编码链接显示的区域边界来相对容易地解决,但是让我们更优雅地解决这个问题,对于一般情况-多行UILabel,而不需要对链接布局有初步的了解。

其中一种方法是使用iOS 7中引入的Text Kit API功能:

// Create instances of NSLayoutManager, NSTextContainer and NSTextStorage
NSLayoutManager *layoutManager = [[NSLayoutManager alloc] init];
NSTextContainer *textContainer = [[NSTextContainer alloc] initWithSize:CGSizeZero];
NSTextStorage *textStorage = [[NSTextStorage alloc] initWithAttributedString:attributedString];

// Configure layoutManager and textStorage
[layoutManager addTextContainer:textContainer];
[textStorage addLayoutManager:layoutManager];

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

将创建和配置的NSLayoutManager, NSTextContainer和NSTextStorage实例保存在类的属性中(很可能是UIViewController的后代)-我们将在其他方法中需要它们。

现在,每当标签改变它的框架,更新textContainer的大小:

- (void)viewDidLayoutSubviews
{
    [super viewDidLayoutSubviews];
    self.textContainer.size = self.label.bounds.size;
}

最后,检测点击是否恰好在链接上:

- (void)handleTapOnLabel:(UITapGestureRecognizer *)tapGesture
{
    CGPoint locationOfTouchInLabel = [tapGesture locationInView:tapGesture.view];
    CGSize labelSize = tapGesture.view.bounds.size;
    CGRect textBoundingBox = [self.layoutManager usedRectForTextContainer:self.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(locationOfTouchInLabel.x - textContainerOffset.x,
                                                         locationOfTouchInLabel.y - textContainerOffset.y);
    NSInteger indexOfCharacter = [self.layoutManager characterIndexForPoint:locationOfTouchInTextContainer
                                                            inTextContainer:self.textContainer
                                   fractionOfDistanceBetweenInsertionPoints:nil];
    NSRange linkRange = NSMakeRange(14, 4); // it's better to save the range somewhere when it was originally used for marking link in attributed string
    if (NSLocationInRange(indexOfCharacter, linkRange)) {
        // Open an URL, or handle the tap on the link in any other way
        [[UIApplication sharedApplication] openURL:[NSURL URLWithString:@"https://stackoverflow.com/"]];
    }
}

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。

(我的回答建立在@NAlexN的精彩回答之上。我不会在这里重复他对每一步的详细解释。)

我发现这是最方便和直接的添加支持可点击的UILabel文本作为类别UITapGestureRecognizer。(你不必使用UITextView的数据检测器,就像一些答案所建议的那样。)

添加以下方法到你的UITapGestureRecognizer类别:

/**
 Returns YES if the tap gesture was within the specified range of the attributed text of the label.
 */
- (BOOL)didTapAttributedTextInLabel:(UILabel *)label inRange:(NSRange)targetRange {
    NSParameterAssert(label != nil);

    CGSize labelSize = label.bounds.size;
    // create instances of NSLayoutManager, NSTextContainer and NSTextStorage
    NSLayoutManager *layoutManager = [[NSLayoutManager alloc] init];
    NSTextContainer *textContainer = [[NSTextContainer alloc] initWithSize:CGSizeZero];
    NSTextStorage *textStorage = [[NSTextStorage alloc] initWithAttributedString:label.attributedText];

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

    // configure textContainer for the label
    textContainer.lineFragmentPadding = 0.0;
    textContainer.lineBreakMode = label.lineBreakMode;
    textContainer.maximumNumberOfLines = label.numberOfLines;
    textContainer.size = labelSize;

    // find the tapped character location and compare it to the specified range
    CGPoint locationOfTouchInLabel = [self locationInView:label];
    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(locationOfTouchInLabel.x - textContainerOffset.x,
                                                         locationOfTouchInLabel.y - textContainerOffset.y);
    NSInteger indexOfCharacter = [layoutManager characterIndexForPoint:locationOfTouchInTextContainer
                                                            inTextContainer:textContainer
                                   fractionOfDistanceBetweenInsertionPoints:nil];
    if (NSLocationInRange(indexOfCharacter, targetRange)) {
        return YES;
    } else {
        return NO;
    }
}

示例代码

// (in your view controller)    
// create your label, gesture recognizer, attributed text, and get the range of the "link" in your label
myLabel.userInteractionEnabled = YES;
[myLabel addGestureRecognizer:
   [[UITapGestureRecognizer alloc] initWithTarget:self 
                                           action:@selector(handleTapOnLabel:)]]; 

// create your attributed text and keep an ivar of your "link" text range
NSAttributedString *plainText;
NSAttributedString *linkText;
plainText = [[NSMutableAttributedString alloc] initWithString:@"Add label links with UITapGestureRecognizer"
                                                   attributes:nil];
linkText = [[NSMutableAttributedString alloc] initWithString:@" Learn more..."
                                                  attributes:@{
                                                      NSForegroundColorAttributeName:[UIColor blueColor]
                                                  }];
NSMutableAttributedString *attrText = [[NSMutableAttributedString alloc] init];
[attrText appendAttributedString:plainText];
[attrText appendAttributedString:linkText];

// ivar -- keep track of the target range so you can compare in the callback
targetRange = NSMakeRange(plainText.length, linkText.length);

手势回调

// handle the gesture recognizer callback and call the category method
- (void)handleTapOnLabel:(UITapGestureRecognizer *)tapGesture {
    BOOL didTapLink = [tapGesture didTapAttributedTextInLabel:myLabel
                                            inRange:targetRange];
    NSLog(@"didTapLink: %d", didTapLink);

}

在Swift 3中工作,将整个代码粘贴在这里

    //****Make sure the textview 'Selectable' = checked, and 'Editable = Unchecked'

import UIKit

class ViewController: UIViewController, UITextViewDelegate {

    @IBOutlet var theNewTextView: UITextView!
    override func viewDidLoad() {
        super.viewDidLoad()

        //****textview = Selectable = checked, and Editable = Unchecked

        theNewTextView.delegate = self

        let theString = NSMutableAttributedString(string: "Agree to Terms")
        let theRange = theString.mutableString.range(of: "Terms")

        theString.addAttribute(NSLinkAttributeName, value: "ContactUs://", range: theRange)

        let theAttribute = [NSForegroundColorAttributeName: UIColor.blue, NSUnderlineStyleAttributeName: NSUnderlineStyle.styleSingle.rawValue] as [String : Any]

        theNewTextView.linkTextAttributes = theAttribute

     theNewTextView.attributedText = theString             

theString.setAttributes(theAttribute, range: theRange)

    }

    func textView(_ textView: UITextView, shouldInteractWith URL: URL, in characterRange: NSRange, interaction: UITextItemInteraction) -> Bool {

        if (URL.scheme?.hasPrefix("ContactUs://"))! {

            return false //interaction not allowed
        }

        //*** Set storyboard id same as VC name
        self.navigationController!.pushViewController((self.storyboard?.instantiateViewController(withIdentifier: "TheLastViewController"))! as UIViewController, animated: true)

        return true
    }

}