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

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
    }

}

对于完全自定义的链接,你需要使用UIWebView -你可以拦截调用,这样当链接被按下时,你可以转到应用程序的其他部分。

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")
     }
    }

基于Charles Gamble的答案,这是我使用的(我删除了一些让我困惑并给我错误索引的行):

- (BOOL)didTapAttributedTextInLabel:(UILabel *)label inRange:(NSRange)targetRange TapGesture:(UIGestureRecognizer*) gesture{
    NSParameterAssert(label != nil);

    // create instances of NSLayoutManager, NSTextContainer and NSTextStorage
    NSLayoutManager *layoutManager = [[NSLayoutManager alloc] init];
    NSTextStorage *textStorage = [[NSTextStorage alloc] initWithAttributedString:label.attributedText];

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

    // configure textContainer for the label
    NSTextContainer *textContainer = [[NSTextContainer alloc] initWithSize:CGSizeMake(label.frame.size.width, label.frame.size.height)];

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

    // find the tapped character location and compare it to the specified range
    CGPoint locationOfTouchInLabel = [gesture locationInView:label];
    [layoutManager addTextContainer:textContainer]; //(move here, not sure it that matter that calling this line after textContainer is set

    NSInteger indexOfCharacter = [layoutManager characterIndexForPoint:locationOfTouchInLabel
                                                           inTextContainer:textContainer
                                  fractionOfDistanceBetweenInsertionPoints:nil];
    if (NSLocationInRange(indexOfCharacter, targetRange)) {
        return YES;
    } else {
        return NO;
    }
}

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")
        }
    }
}