如何在Swift 3中仅针对UILabel的特定范围设置轻击手势 [英] How to set up a tap gesture only for specific ranges of a UILabel in Swift 3

问题描述

我将attributed string设置为UILabel，而multiple underlines，colors如下图所示

I have an attributed string set to UILabel with multiple underlines , colors like below image

我知道如何为整个标签设置轻敲手势(启用user interaction)，下面是我的代码，这是我所做的工作，包括设置underline和设置用于multiple ranges.

and I know How to setup a tap gesture for whole label (with enabling user interaction) and below is my code for what I have done including setting up underline and setting up font colors for 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"时会触发其他功能，而当用户点击隐私权政策"时会触发另一个功能.我怎样才能做到这一点.
• The tap gesture work for whole label. what I want is when user tap on "terms and conditions" fire a different function and and when user tap on "privacy policy" fire another different function. how can I do that.

注意:我想触发两个不同的功能，一个用于条款和条件"轻按，另一个用于隐私权政策"轻按，但不希望 打开链接

Note : I want to fire two different functions one for "terms and conditions" tap, and other for "privacy policy" tap, and do not want to just open links

推荐答案

    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)

    }
}*

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