swift 在UILabel中创建多个可指向链接

Posted 2021-05-19

// MARK: Multiple Tappable Links in a UILabel
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)
    }
    
}
// add uilabel then setup
func setupMultipleTapLabel() {
        lblPrivacyTerm.text = "By signing up you agree to our Terms of service and Privacy policy"
        let text = (lblPrivacyTerm.text)!
        let underlineAttriString = NSMutableAttributedString(string: text)
        let range1 = (text as NSString).range(of: "Terms of service")
        underlineAttriString.addAttribute(NSUnderlineStyleAttributeName, value: NSUnderlineStyle.styleSingle.rawValue, range: range1)
        let range2 = (text as NSString).range(of: "Privacy policy")
        underlineAttriString.addAttribute(NSUnderlineStyleAttributeName, value: NSUnderlineStyle.styleSingle.rawValue, range: range2)
        lblPrivacyTerm.attributedText = underlineAttriString
        let tapAction = UITapGestureRecognizer(target: self, action: #selector(self.tapLabel(gesture:)))
        lblPrivacyTerm.isUserInteractionEnabled = true
        lblPrivacyTerm.addGestureRecognizer(tapAction)
    }
    @IBAction func tapLabel(gesture: UITapGestureRecognizer) {
        let text = (lblPrivacyTerm.text)!
        let termsRange = (text as NSString).range(of: "Terms of service")
        let privacyRange = (text as NSString).range(of: "Privacy policy")
        
        if gesture.didTapAttributedTextInLabel(label: lblPrivacyTerm, inRange: termsRange) {
            print("Terms of service")
        } else if gesture.didTapAttributedTextInLabel(label: lblPrivacyTerm, inRange: privacyRange) {
             print("Privacy policy")
        } else {
            print("Tapped none")
        }
    }