如何仅在 Swift 3 中为特定范围的 UILabel 设置点击手势

Question

我有一个 attributed string 设置为 UILabel 和 multiple underlines ， colors 如下图所示

我知道如何为整个标签设置点击手势（启用user interaction）和下面是我的代码我所做的包括设置underline和设置@987654330 @ 代表multiple ranges。

import UIKit

class ViewController: UIViewController {


    @IBOutlet weak var mylabel: UILabel!

    var theString = "I have agree with the terms and conditions and privacy policy"

    override func viewDidLoad() {
        super.viewDidLoad()

        mylabel.text = theString


        let tap = UITapGestureRecognizer(target: self, action: #selector(ViewController.printme))
        mylabel.addGestureRecognizer(tap)

        setUnderline(theText: theString)

        // Do any additional setup after loading the view, typically from a nib.
    }

    func printme() {
        print("print this")
    }

    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    }

    func setUnderline(theText : String) {
        //set up underline
        let textRange1 = NSMakeRange(22, 19)
        let textRange2 = NSMakeRange(47, (theText.characters.count-47))
        let attributedText = NSMutableAttributedString(string : theText)
        attributedText.addAttribute(NSUnderlineStyleAttributeName, value: NSUnderlineStyle.styleSingle.rawValue, range: textRange1)
        attributedText.addAttribute(NSUnderlineStyleAttributeName, value: NSUnderlineStyle.styleSingle.rawValue, range: textRange2)


        //setup colors
        attributedText.addAttribute(NSForegroundColorAttributeName, value: UIColor.red, range: NSRange(location: 22,length: 20))
        attributedText.addAttribute(NSForegroundColorAttributeName, value: UIColor.red, range: NSRange(location: 47,length: (theText.characters.count-47)))

        mylabel.attributedText = attributedText

    }

• tap 手势适用于whole label。我想要的是当用户点击“条款和条件”时触发不同的功能，并且当用户点击“隐私政策”时触发另一个不同的功能。我怎样才能做到这一点。

注意：我想触发两个不同的功能，一个用于“条款和条件”点击，另一个用于“隐私政策”点击，并且不想只 打开链接

Answer 1

    import UIKit

    protocol SSGastureDelegate:NSObjectProtocol {
        func callBack()
    }
    class SSUnderLineLabel: UILabel {
        var tapGesture: UITapGestureRecognizer?

      //Make weak refernece for SSGastureDelegate
       weak var delegate:SSGastureDelegate?

        required init(coder aDecoder: NSCoder) {
            super.init(coder: aDecoder)!
            self.initialization()
        }
        override init(frame: CGRect) {
            super.init(frame: frame)
            self.initialization()
        }

        func initialization(){
            let newsString: NSMutableAttributedString = NSMutableAttributedString(string: self.text!)
            let textRange = NSString(string: self.text!)
            let substringRange = textRange.range(of: "Terms and Conditions") // You can add here for own specific under line substring
            newsString.addAttribute(NSUnderlineStyleAttributeName, value: NSUnderlineStyle.styleSingle.rawValue, range: substringRange)
           // self.attributedText = newsString.copy() as? NSAttributedString
            self.attributedText = newsString
            self.tapGesture = UITapGestureRecognizer(target: self, action: #selector(tapResponse))
            self.isUserInteractionEnabled =  true
            self.addGestureRecognizer(tapGesture!)

        }

        func tapResponse(recognizer: UITapGestureRecognizer) {

            let text = (self.text)!
            let termsRange = (text as NSString).range(of: "Terms and Conditions")
            if (tapGesture?.didTapAttributedTextInLabel(label: self, inRange: termsRange))! {
                print("Tapped terms conditions")
                self.delegate?.callBack()
            }
            else {
                print("Tapped none ")
            }
        }

    }

    //MARK:UITapGestureRecognizer Extension
    //MARK:
    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)
        }

    }*`enter code here`




**How to use it:**
Assign this class for your label and follow these steps:
Demo for use class:

ViewController.swift
//===============

class ViewController: UIViewController,SSGastureDelegate {
 @IBOutlet var underlineLbl: SSUnderLineLabel!

 override func viewDidLoad() {
      super.viewDidLoad()
     self.underlineLbl.delegate = self
 }
//Implement Delegate Method
 func callBack()
    {
//Open a specific vc for underline tap are`enter code here`a.
        let termsconditionsVC = storyboard?.instantiateViewController(withIdentifier: "TermsConditionsVC") as! TermsConditionsVC
        self.present(termsconditions, animated: true, completion: nil)

    }
}*

Answer 2

我看到您需要您的条款和隐私链接是可点击的，ios 提供的简单方法是 AttributedString，使用以下代码：

let theString = "I have agree with the terms and conditions and privacy policy"
let someAttributedString = NSMutableAttributedString(string: theString)
someAttributedString.addAttribute(NSLinkAttributeName, value: "http://www.google.com", range: NSMakeRange(22, 20))
titleLabel.attributedText = someAttributedString

TTTAttributedLabel 可能是您的最佳解决方案：https://github.com/TTTAttributedLabel/TTTAttributedLabel

TTTAttributedLabel 有以下委托

- (void)attributedLabel:(__unused TTTAttributedLabel *)label
   didSelectLinkWithURL:(NSURL *)url
{
 //do whatever you want
}

此外，如果您需要点击手势的解决方案，您可以在手势点击上找到点并计算以检查它被点击的位置以通过gestureRecognizer.locationInView 方法执行您的操作