Question

修改

请参阅我的答案以获得完整的解决方案：

我设法使用UITextView代替UILabel来解决这个问题。我写了一个类，使UITextView表现得像UILabel，但链接检测完全准确。

我已设法使用NSMutableAttributedString设置链接的样式而没有问题，但我无法准确检测到哪个字符已被点击。我已经尝试了this question中的所有解决方案（我可以转换为Swift 4代码），但没有运气。

以下代码有效，但无法准确检测到哪个字符被点击并获取了错误的链接位置：

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)
    print(indexOfCharacter)
    return NSLocationInRange(indexOfCharacter, targetRange)
}

Answer 1

如果您不介意重写代码，则应使用UITextView代替UILabel。

您可以通过设置UITextView的{{1}}轻松检测链接，并实施委托功能以检索您点击的网址。

dataDetectorTypes

https://developer.apple.com/documentation/uikit/uitextviewdelegate/1649337-textview

Answer 2

我设法使用element.find_elements(By.TAG_NAME,"td")[0].get_attribute("id")代替UITextView来解决此问题。我最初不想使用UILabel，因为我需要该元素的行为类似于UITextView，而UILabel可能会导致滚动问题，而且它的目的是什么使用，是可编辑的文字。我编写的以下课程使UITextView表现得像UITextView，但具有完全准确的点击检测且没有滚动问题：

UILabel

函数import UIKit class ClickableLabelTextView: UITextView { var delegate: DelegateForClickEvent? var ranges:[(start: Int, end: Int)] = [] var page: String = "" var paragraph: Int? var clickedLink: (() -> Void)? var pressedTime: Int? var startTime: TimeInterval? override func awakeFromNib() { super.awakeFromNib() self.textContainerInset = UIEdgeInsets.zero self.textContainer.lineFragmentPadding = 0 self.delaysContentTouches = true self.isEditable = false self.isUserInteractionEnabled = true self.isSelectable = false } override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) { startTime = Date().timeIntervalSinceReferenceDate } override func touchesEnded(_ touches: Set<UITouch>, with event: UIEvent?) { if let clickedLink = clickedLink { if let startTime = startTime { self.startTime = nil if (Date().timeIntervalSinceReferenceDate - startTime <= 0.2) { clickedLink() } } } } override func hitTest(_ point: CGPoint, with event: UIEvent?) -> UIView? { var location = point location.x -= self.textContainerInset.left location.y -= self.textContainerInset.top if location.x > 0 && location.y > 0 { let index = self.layoutManager.characterIndex(for: location, in: self.textContainer, fractionOfDistanceBetweenInsertionPoints: nil) var count = 0 for range in ranges { if index >= range.start && index < range.end { clickedLink = { self.delegate?.clickedLink(page: self.page, paragraph: self.paragraph, linkNo: count) } return self } count += 1 } } clickedLink = nil return nil } }被多次调用但不会导致问题，因为hitTest每次点击只会被调用一次。我尝试为不同的观点停用clickedLink()，但没有做出任何帮助，也没有必要。

要使用该课程，只需将其添加到isUserInteractionEnabled即可。如果您在Xcode编辑器中使用UITextView，请在编辑器中为autoLayout禁用Scrolling Enabled以避免布局警告。

在UITextView文件中包含与Swift文件一起使用的代码（在我的情况下是xib的类），您需要为可点击的textView设置以下变量：

UITableViewCell - ranges
UITextView - page标识包含String
UITextView - 如果您有多个可点击的paragraph，请为每个人分配一个号码
UITextView - 将点击事件委派给您可以处理它们的地方。

然后，您需要为delegate：

创建协议

delegate

传递到protocol DelegateName { func clickedLink(page: String, paragraph: Int?, linkNo: Int?) }的变量为您提供了解所点击链接所需的所有信息。

Answer 3

您可以使用MLLabel库。 MLLabel是UIlabel的子类。该库有一个类MLLinkLabel，它是MLLabel的子类。这意味着您可以使用它来代替UIlabel（即使在界面构建器中，只需拖动UILabel并将其更改为MLLinkLabel）

MLLinkLabel可以为您提供帮助，非常简单。这是一个例子：

    label.didClickLinkBlock = {(link, linkText, label) -> Void in

        //Here you can check the type of the link and do whatever you want.
        switch link!.linkType {
        case .email:
            break
        case .none:
             break
        case .URL:
             break
        case .phoneNumber:
             break
        case .userHandle:
             break
        case .hashtag:
             break
        case .other:
             break
        }

    }

您可以在GitHub https://github.com/molon/MLLabel

中查看该库

以下是我使用其中一个MLLabel的应用程序的屏幕截图。

Answer 4

我想避免发布答案，因为它更多是对Dan Bray自己答案的评论（由于缺乏代表而无法发表评论）。但是，我仍然认为值得分享。

为了方便起见，我为Dan Bray的答案做了一些小改进（我认为是这样的改进）：

我发现使用范围和设置textView有点尴尬因此我用textLink dict替换了那个部分来存储链接字符串及其各自的目标。实现viewController只需要将其设置为初始化textView。
我在链接中添加了下划线样式（保持字体等来自界面构建器）。您可以在此处添加自己的样式（如蓝色字体等）。
我重新设计了回调的签名，使其更容易处理。
请注意，我还必须将delegate重命名为linkDelegate，因为UITextViews已经有了委托。

TextView：

import UIKit

class LinkTextView: UITextView {
  private var callback: (() -> Void)?
  private var pressedTime: Int?
  private var startTime: TimeInterval?
  private var initialized = false
  var linkDelegate: LinkTextViewDelegate?
  var textLinks: [String : String] = Dictionary() {
    didSet {
        initialized = false
        styleTextLinks()
    }
  }

  override func awakeFromNib() {
    super.awakeFromNib()
    self.textContainerInset = UIEdgeInsets.zero
    self.textContainer.lineFragmentPadding = 0
    self.delaysContentTouches = true
    self.isEditable = false
    self.isUserInteractionEnabled = true
    self.isSelectable = false
    styleTextLinks()
  }

  private func styleTextLinks() {
    guard !initialized && !textLinks.isEmpty else {
        return
    }
    initialized = true

    let alignmentStyle = NSMutableParagraphStyle()
    alignmentStyle.alignment = self.textAlignment        

    let input = self.text ?? ""
    let attributes: [NSAttributedStringKey : Any] = [
        NSAttributedStringKey.foregroundColor : self.textColor!,
        NSAttributedStringKey.font : self.font!,
        .paragraphStyle : alignmentStyle
    ]
    let attributedString = NSMutableAttributedString(string: input, attributes: attributes)

    for textLink in textLinks {
        let range = (input as NSString).range(of: textLink.0)
        if range.lowerBound != NSNotFound {
            attributedString.addAttribute(.underlineStyle, value: NSUnderlineStyle.styleSingle.rawValue, range: range)
        }
    }

    attributedText = attributedString
  }

  override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) {
    startTime = Date().timeIntervalSinceReferenceDate
  }

  override func touchesEnded(_ touches: Set<UITouch>, with event: UIEvent?) {
    if let callback = callback {
        if let startTime = startTime {
            self.startTime = nil
            if (Date().timeIntervalSinceReferenceDate - startTime <= 0.2) {
                callback()
            }
        }
    }
  }

  override func hitTest(_ point: CGPoint, with event: UIEvent?) -> UIView? {
    var location = point
    location.x -= self.textContainerInset.left
    location.y -= self.textContainerInset.top
    if location.x > 0 && location.y > 0 {
        let index = self.layoutManager.characterIndex(for: location, in: self.textContainer, fractionOfDistanceBetweenInsertionPoints: nil)
        for textLink in textLinks {
            let range = ((text ?? "") as NSString).range(of: textLink.0)
            if NSLocationInRange(index, range) {
                callback = {
                    self.linkDelegate?.didTap(text: textLink.0, withLink: textLink.1, inTextView: self)
                }
                return self
            }
        }
    }
    callback = nil
    return nil
  }
}

代表：

import Foundation

protocol LinkTextViewDelegate {
  func didTap(text: String, withLink link: String, inTextView textView: LinkTextView)
}

实现viewController：

override func viewDidLoad() {
  super.viewDidLoad()
  myLinkTextView.linkDelegate = self
  myLinkTextView.textLinks = [
    "click here" : "https://wwww.google.com",
    "or here" : "#myOwnAppHook"
  ]
}

最后但并非最不重要的是非常感谢Dan Bray，毕竟这是解决方案！

Answer 5

如果你需要一个Label的子类，解决方案可能就像在操场上准备的那样（因为这只是一个草案，因为某些点应该被优化）：

//: A UIKit based Playground for presenting user interface

import UIKit
import PlaygroundSupport

extension String {
    // MARK: - String+RangeDetection

    func rangesOfPattern(patternString: String) -> [Range<Index>] {
        var ranges : [Range<Index>] = []

        let patternCharactersCount = patternString.count
        let strCharactersCount = self.count
        if  strCharactersCount >= patternCharactersCount {

            for i in 0...(strCharactersCount - patternCharactersCount) {
                let from:Index = self.index(self.startIndex, offsetBy:i)
                if let to:Index = self.index(from, offsetBy:patternCharactersCount, limitedBy: self.endIndex) {

                    if patternString == self[from..<to] {
                        ranges.append(from..<to)
                    }
                }
            }
        }

        return ranges
    }

    func nsRange(from range: Range<String.Index>) -> NSRange? {
        let utf16view = self.utf16
        if let from = range.lowerBound.samePosition(in: utf16view),
            let to = range.upperBound.samePosition(in: utf16view) {
            return NSMakeRange(utf16view.distance(from: utf16view.startIndex, to: from),
                               utf16view.distance(from: from, to: to))
        }
        return nil
    }

    func range(from nsRange: NSRange) -> Range<String.Index>? {
        guard
            let from16 = utf16.index(utf16.startIndex, offsetBy: nsRange.location, limitedBy: utf16.endIndex),
            let to16 = utf16.index(from16, offsetBy: nsRange.length, limitedBy: utf16.endIndex),
            let from = String.Index(from16, within: self),
            let to = String.Index(to16, within: self)
            else { return nil }
        return from ..< to
    }
}

final class TappableLabel: UILabel {

    private struct Const {
        static let DetectableAttributeName = "DetectableAttributeName"
    }

    var detectableText: String?
    var displayableContentText: String?

    var mainTextAttributes:[NSAttributedStringKey : AnyObject] = [:]
    var tappableTextAttributes:[NSAttributedStringKey : AnyObject] = [:]

    var didDetectTapOnText:((_:String, NSRange) -> ())?

    private var tapGesture:UITapGestureRecognizer?

    // MARK: - Public

    func performPreparation() {
        DispatchQueue.main.async {
            self.prepareDetection()
        }
    }

    // MARK: - Private

    private func prepareDetection() {

        guard let searchableString = self.displayableContentText else { return }
        let attributtedString = NSMutableAttributedString(string: searchableString, attributes: mainTextAttributes)

        if let detectionText = detectableText {

            var attributesForDetection:[NSAttributedStringKey : AnyObject] = [
                NSAttributedStringKey(rawValue: Const.DetectableAttributeName) : "UserAction" as AnyObject
            ]
            tappableTextAttributes.forEach {
                attributesForDetection.updateValue($1, forKey: $0)
            }

            for (_ ,range) in searchableString.rangesOfPattern(patternString: detectionText).enumerated() {
                let tappableRange = searchableString.nsRange(from: range)
                attributtedString.addAttributes(attributesForDetection, range: tappableRange!)
            }

            if self.tapGesture == nil {
                setupTouch()
            }
        }

        text = nil
        attributedText = attributtedString
    }

    private func setupTouch() {
        let tapGesture = UITapGestureRecognizer(target: self, action: #selector(TappableLabel.detectTouch(_:)))
        addGestureRecognizer(tapGesture)
        self.tapGesture = tapGesture
    }

    @objc private func detectTouch(_ gesture: UITapGestureRecognizer) {
        guard let attributedText = attributedText, gesture.state == .ended else {
            return
        }

        let textContainer = NSTextContainer(size: bounds.size)
        textContainer.lineFragmentPadding = 0.0
        textContainer.lineBreakMode = lineBreakMode
        textContainer.maximumNumberOfLines = numberOfLines

        let layoutManager = NSLayoutManager()
        layoutManager.addTextContainer(textContainer)

        let textStorage = NSTextStorage(attributedString: attributedText)
        textStorage.addAttribute(NSAttributedStringKey.font, value: font, range: NSMakeRange(0, attributedText.length))
        textStorage.addLayoutManager(layoutManager)

        let locationOfTouchInLabel = gesture.location(in: gesture.view)

        let textBoundingBox = layoutManager.usedRect(for: textContainer)
        var alignmentOffset: CGFloat!
        switch textAlignment {
        case .left, .natural, .justified:
            alignmentOffset = 0.0
        case .center:
            alignmentOffset = 0.5
        case .right:
            alignmentOffset = 1.0
        }
        let xOffset = ((bounds.size.width - textBoundingBox.size.width) * alignmentOffset) - textBoundingBox.origin.x
        let yOffset = ((bounds.size.height - textBoundingBox.size.height) * alignmentOffset) - textBoundingBox.origin.y
        let locationOfTouchInTextContainer = CGPoint(x: locationOfTouchInLabel.x - xOffset, y: locationOfTouchInLabel.y - yOffset)

        let characterIndex = layoutManager.characterIndex(for: locationOfTouchInTextContainer, in: textContainer, fractionOfDistanceBetweenInsertionPoints: nil)

        if characterIndex < textStorage.length {
            let tapRange = NSRange(location: characterIndex, length: 1)
            let substring = (self.attributedText?.string as? NSString)?.substring(with: tapRange)

            let attributeName = Const.DetectableAttributeName
            let attributeValue = self.attributedText?.attribute(NSAttributedStringKey(rawValue: attributeName), at: characterIndex, effectiveRange: nil) as? String
            if let _ = attributeValue,
                let substring = substring {
                DispatchQueue.main.async {
                    self.didDetectTapOnText?(substring, tapRange)
                }
            }
        }

    }
}


class MyViewController : UIViewController {
    override func loadView() {
        let view = UIView()
        view.backgroundColor = .white

        let label = TappableLabel()
        label.frame = CGRect(x: 150, y: 200, width: 200, height: 20)
        label.displayableContentText = "Hello World! stackoverflow"
        label.textColor = .black
        label.isUserInteractionEnabled = true

        label.detectableText = "World!"
        label.didDetectTapOnText = { (value1, value2) in
            print("\(value1) - \(value2)\n")
        }
        label.performPreparation()

        view.addSubview(label)
        self.view = view
    }
}
// Present the view controller in the Live View window
PlaygroundPage.current.liveView = MyViewController()

演示：

Answer 6

要使Dan Bray的上述解决方案对我有用，我必须致电super.hitTest(point, with:event)而不是返回nil。否则，不会调用touchesBegan和touchesEnded。我在UIScrollView中使用了textViews。

override func hitTest(_ point: CGPoint, with event: UIEvent?) -> UIView? {
    var location = point
    location.x -= self.textContainerInset.left
    location.y -= self.textContainerInset.top
    if location.x > 0 && location.y > 0 {


    let index = self.layoutManager.characterIndex(for: location, in: self.textContainer, fractionOfDistanceBetweenInsertionPoints: nil)
        for textLink in textLinks {
            let range = ((text ?? "") as NSString).range(of: textLink.0)
            if NSLocationInRange(index, range) {
                callback = {
                    self.linkDelegate?.didTap(text: textLink.0, withLink: textLink.1, inTextView: self)
                }
                return self
            }
        }
    }
    callback = nil
    return super.hitTest(point, with:event)
}

如何准确检测是否在Swift 4中的UILabels内点击了链接？

6 个答案: