斯威夫特5.2

我在之前的回答中发现了多行文本标签的几个问题，所以我给出了我最终的工作解决方案。

它解决了多行和文本对齐的问题。

    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 textAligmentOffset = aligmentOffset(for: label)
        let textContainerOffset = CGPoint(x: (labelSize.width - textBoundingBox.size.width) * textAligmentOffset - textBoundingBox.origin.x,
                                          y: (labelSize.height - textBoundingBox.size.height) * textAligmentOffset - textBoundingBox.origin.y)
        let locationOfTouchInTextContainer = CGPoint(x: (locationOfTouchInLabel.x - textContainerOffset.x),
                                                     y: 0 )
        // Adjust for multiple lines of text
        let lineModifier = Int(floor(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)
        return NSLocationInRange(adjustedRange, targetRange)
    }
    
    private func aligmentOffset(for label: UILabel) -> CGFloat {
        switch label.textAlignment {
        case .left, .natural, .justified:
            return 0.0
        case .center:
            return 0.5
        case .right:
            return 1.0
        @unknown default:
            return 0.0
        }
    }

以下是基于@Luca Davanzo的回答，重写touchesBegan事件而不是轻触手势:

import UIKit

public protocol TapableLabelDelegate: NSObjectProtocol {
   func tapableLabel(_ label: TapableLabel, didTapUrl url: String, atRange range: NSRange)
}

public class TapableLabel: UILabel {

private var links: [String: NSRange] = [:]
private(set) var layoutManager = NSLayoutManager()
private(set) var textContainer = NSTextContainer(size: CGSize.zero)
private(set) var textStorage = NSTextStorage() {
    didSet {
        textStorage.addLayoutManager(layoutManager)
    }
}

public weak var delegate: TapableLabelDelegate?

public override var attributedText: NSAttributedString? {
    didSet {
        if let attributedText = attributedText {
            textStorage = NSTextStorage(attributedString: attributedText)
        } else {
            textStorage = NSTextStorage()
            links = [:]
        }
    }
}

public override var lineBreakMode: NSLineBreakMode {
    didSet {
        textContainer.lineBreakMode = lineBreakMode
    }
}

public override var numberOfLines: Int {
    didSet {
        textContainer.maximumNumberOfLines = numberOfLines
    }
}


public override init(frame: CGRect) {
    super.init(frame: frame)
    setup()
}

public required init?(coder aDecoder: NSCoder) {
    super.init(coder: aDecoder)
    setup()
}

public override func layoutSubviews() {
    super.layoutSubviews()
    textContainer.size = bounds.size
}


/// addLinks
///
/// - Parameters:
///   - text: text of link
///   - url: link url string
public func addLink(_ text: String, withURL url: String) {
    guard let theText = attributedText?.string as? NSString else {
        return
    }

    let range = theText.range(of: text)

    guard range.location !=  NSNotFound else {
        return
    }

    links[url] = range
}

private func setup() {
    isUserInteractionEnabled = true
    layoutManager.addTextContainer(textContainer)
    textContainer.lineFragmentPadding = 0
    textContainer.lineBreakMode = lineBreakMode
    textContainer.maximumNumberOfLines  = numberOfLines
}

public override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) {
    guard let locationOfTouch = touches.first?.location(in: self) else {
        return
    }

    textContainer.size = bounds.size
    let indexOfCharacter = layoutManager.glyphIndex(for: locationOfTouch, in: textContainer)

    for (urlString, range) in links {
        if NSLocationInRange(indexOfCharacter, range), let url = URL(string: urlString) {
            delegate?.tapableLabel(self, didTapUrl: urlString, atRange: range)
        }
    }
}}

有些答案并不如我所料。这是Swift解决方案，也支持textAlignment和多行。不需要子类化，只是这个UITapGestureRecognizer扩展:

import UIKit


extension UITapGestureRecognizer {
    
    func didTapAttributedString(_ string: String, in label: UILabel) -> Bool {
        
        guard let text = label.text else {
            
            return false
        }
        
        let range = (text as NSString).range(of: string)
        return self.didTapAttributedText(label: label, inRange: range)
    }
    
    private func didTapAttributedText(label: UILabel, inRange targetRange: NSRange) -> Bool {
        
        guard let attributedText = label.attributedText else {
            
            assertionFailure("attributedText must be set")
            return false
        }
        
        let textContainer = createTextContainer(for: label)
        
        let layoutManager = NSLayoutManager()
        layoutManager.addTextContainer(textContainer)
        
        let textStorage = NSTextStorage(attributedString: attributedText)
        if let font = label.font {
            
            textStorage.addAttribute(NSAttributedString.Key.font, value: font, range: NSMakeRange(0, attributedText.length))
        }
        textStorage.addLayoutManager(layoutManager)
        
        let locationOfTouchInLabel = location(in: label)
        let textBoundingBox = layoutManager.usedRect(for: textContainer)
        let alignmentOffset = aligmentOffset(for: label)
        
        let xOffset = ((label.bounds.size.width - textBoundingBox.size.width) * alignmentOffset) - textBoundingBox.origin.x
        let yOffset = ((label.bounds.size.height - textBoundingBox.size.height) * alignmentOffset) - textBoundingBox.origin.y
        let locationOfTouchInTextContainer = CGPoint(x: locationOfTouchInLabel.x - xOffset, y: locationOfTouchInLabel.y - yOffset)
        
        let characterTapped = layoutManager.characterIndex(for: locationOfTouchInTextContainer, in: textContainer, fractionOfDistanceBetweenInsertionPoints: nil)
        
        let lineTapped = Int(ceil(locationOfTouchInLabel.y / label.font.lineHeight)) - 1
        let rightMostPointInLineTapped = CGPoint(x: label.bounds.size.width, y: label.font.lineHeight * CGFloat(lineTapped))
        let charsInLineTapped = layoutManager.characterIndex(for: rightMostPointInLineTapped, in: textContainer, fractionOfDistanceBetweenInsertionPoints: nil)
        
        return characterTapped < charsInLineTapped ? targetRange.contains(characterTapped) : false
    }
    
    private func createTextContainer(for label: UILabel) -> NSTextContainer {
        
        let textContainer = NSTextContainer(size: label.bounds.size)
        textContainer.lineFragmentPadding = 0.0
        textContainer.lineBreakMode = label.lineBreakMode
        textContainer.maximumNumberOfLines = label.numberOfLines
        return textContainer
    }
    
    private func aligmentOffset(for label: UILabel) -> CGFloat {
        
        switch label.textAlignment {
            
        case .left, .natural, .justified:
            
            return 0.0
        case .center:
            
            return 0.5
        case .right:
            
            return 1.0
            
            @unknown default:
            
            return 0.0
        }
    }
}

用法:

class ViewController: UIViewController {
    
    @IBOutlet var label : UILabel!
    
    let selectableString1 = "consectetur"
    let selectableString2 = "cupidatat"
    
    override func viewDidLoad() {
        super.viewDidLoad()
        
        let text = "Lorem ipsum dolor sit amet, \(selectableString1) adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat \(selectableString2) non proident, sunt in culpa qui officia deserunt mollit anim id est laborum."
        label.attributedText = NSMutableAttributedString(attributedString: NSAttributedString(string: text))
        
        let tapGesture = UITapGestureRecognizer(target: self, action: #selector(labelTapped))
        label.addGestureRecognizer(tapGesture)
        label.isUserInteractionEnabled = true
    }
    
    @objc func labelTapped(gesture: UITapGestureRecognizer) {
        
        if gesture.didTapAttributedString(selectableString1, in: label) {
            
            print("\(selectableString1) tapped")
        } else if gesture.didTapAttributedString(selectableString2, in: label) {
            
            print("\(selectableString2) tapped")
        } else {
            
            print("Text tapped")
        }
    }
}

这是一个Objective-C类别，它支持现有UILabel中的可点击链接。attributedText字符串，利用现有的NSLinkAttributeName属性。

@interface UILabel (GSBClickableLinks) <UIGestureRecognizerDelegate>
@property BOOL enableLinks;
@end

#import <objc/runtime.h>
static const void *INDEX;
static const void *TAP;

@implementation UILabel (GSBClickableLinks)

- (void)setEnableLinks:(BOOL)enableLinks
{
    UITapGestureRecognizer *tap = objc_getAssociatedObject(self, &TAP); // retreive tap
    if (enableLinks && !tap) { // add a gestureRegonzier to the UILabel to detect taps
        tap = [UITapGestureRecognizer.alloc initWithTarget:self action:@selector(openLink)];
        tap.delegate = self;
        [self addGestureRecognizer:tap];
        objc_setAssociatedObject(self, &TAP, tap, OBJC_ASSOCIATION_RETAIN_NONATOMIC); // save tap
    }
    self.userInteractionEnabled = enableLinks; // note - when false UILAbel wont receive taps, hence disable links
}

- (BOOL)enableLinks
{
    return (BOOL)objc_getAssociatedObject(self, &TAP); // ie tap != nil
}

// First check whether user tapped on a link within the attributedText of the label.
// If so, then the our label's gestureRecogizer will subsequently fire, and open the corresponding NSLinkAttributeName.
// If not, then the tap will get passed along, eg to the enclosing UITableViewCell...
// Note: save which character in the attributedText was clicked so that we dont have to redo everything again in openLink.
- (BOOL)gestureRecognizerShouldBegin:(UIGestureRecognizer *)gestureRecognizer
{
    if (gestureRecognizer != objc_getAssociatedObject(self, &TAP)) return YES; // dont block other gestures (eg swipe)

    // Re-layout the attributedText to find out what was tapped
    NSTextContainer *textContainer = [NSTextContainer.alloc initWithSize:self.frame.size];
    textContainer.lineFragmentPadding = 0;
    textContainer.maximumNumberOfLines = self.numberOfLines;
    textContainer.lineBreakMode = self.lineBreakMode;
    NSLayoutManager *layoutManager = NSLayoutManager.new;
    [layoutManager addTextContainer:textContainer];
    NSTextStorage *textStorage = [NSTextStorage.alloc initWithAttributedString:self.attributedText];
    [textStorage addLayoutManager:layoutManager];

    NSUInteger index = [layoutManager characterIndexForPoint:[gestureRecognizer locationInView:self]
                                             inTextContainer:textContainer
                    fractionOfDistanceBetweenInsertionPoints:NULL];
    objc_setAssociatedObject(self, &INDEX, @(index), OBJC_ASSOCIATION_RETAIN_NONATOMIC); // save index

    return (BOOL)[self.attributedText attribute:NSLinkAttributeName atIndex:index effectiveRange:NULL]; // tapped on part of a link?
}

- (void)openLink
{
    NSUInteger index = [objc_getAssociatedObject(self, &INDEX) unsignedIntegerValue]; // retrieve index
    NSURL *url = [self.attributedText attribute:NSLinkAttributeName atIndex:index effectiveRange:NULL];
    if (url && [UIApplication.sharedApplication canOpenURL:url]) [UIApplication.sharedApplication openURL:url];
}

@end 

这将通过一个UILabel子类(即没有objc_getAssociatedObject的混乱)来完成，但如果你像我一样，你更喜欢避免不必要的(第三方)子类，只是为了给现有的UIKit类添加一些额外的功能。此外，这有一个漂亮的地方，它添加了任何现有的UILabel的点击链接，例如现有的UITableViewCells!

我已经试着让它尽可能的最小化侵入性通过使用现有的NSLinkAttributeName属性在NSAttributedString中已经可用。所以很简单:

NSURL *myURL = [NSURL URLWithString:@"http://www.google.com"];
NSMutableAttributedString *myString = [NSMutableAttributedString.alloc initWithString:@"This string has a clickable link: "];
[myString appendAttributedString:[NSAttributedString.alloc initWithString:@"click here" attributes:@{NSLinkAttributeName:myURL}]];
...
myLabel.attributedText = myString;
myLabel.enableLinks = YES; // yes, that's all! :-)

基本上，它通过添加一个UIGestureRecognizer到你的UILabel来工作。最难的工作是在gestureRecognizerShouldBegin:中完成的，它会重新布局attributedText字符串，以找出被点击的字符。如果这个字符是NSLinkAttributeName的一部分，那么手势识别器将随后触发，检索相应的URL(从NSLinkAttributeName值)，并打开每个通常的[UIApplication。sharedApplication openURL:url进程。

注意:通过在gestureRecognizerShouldBegin:中执行所有这些操作，如果你没有碰巧点击标签中的链接，事件就会被传递。因此，例如，你的UITableViewCell将捕获点击链接，但其他行为正常(选择单元格，取消选择，滚动，…)。

我把它放在了GitHub仓库里。 改编自Kai Burghardt的SO帖子。

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")
     }
    }

    NSString *string = name;
    NSError *error = NULL;
    NSDataDetector *detector =
    [NSDataDetector dataDetectorWithTypes:(NSTextCheckingTypes)NSTextCheckingTypeLink | NSTextCheckingTypePhoneNumber
                                    error:&error];
    NSArray *matches = [detector matchesInString:string
                                         options:0
                                           range:NSMakeRange(0, [string length])];
    for (NSTextCheckingResult *match in matches)
    {
        if (([match resultType] == NSTextCheckingTypePhoneNumber))
        {
            NSString *phoneNumber = [match phoneNumber];
            NSLog(@" Phone Number is :%@",phoneNumber);
            label.enabledTextCheckingTypes = NSTextCheckingTypePhoneNumber;
        }

        if(([match resultType] == NSTextCheckingTypeLink))
        {
            NSURL *email = [match URL];
            NSLog(@"Email is  :%@",email);
            label.enabledTextCheckingTypes = NSTextCheckingTypeLink;
        }

        if (([match resultType] == NSTextCheckingTypeLink))
        {
            NSURL *url = [match URL];
            NSLog(@"URL is  :%@",url);
            label.enabledTextCheckingTypes = NSTextCheckingTypeLink;
        }
    }

    label.text =name;
}