如何使 NSAttributedString 鏈接可點擊

Question

我需要將數字顯示為來自字符串輸入（包含字母和數字）的可點擊鏈接，並且在點擊該數字時它應該打開一個 iOS 呼叫撥號器並撥打該號碼。

下面是我目前嘗試過的方法，使數字看起來像一個可點擊的數字，並且 rest 所有文本都作為普通默認文本，黑色低於 formattedText var 已定義，

var formattedText: NSAttributedString{
let message = "Hey you can dial up {88 22 333} number for further assistance"
let linkRange = (message as NSString).range(of: fetchNumber) //fetchNumber method returns the content residing inside flower braces..

guard linkRange.location != NSNotFound else {return nil}
let finalString = NSMutableAttributedString(string: message, attributes:[.font: UIFont.scaledFont(from: .baseText16), foregroundColor: .black])
finalString.addAttributes([.foregroundColor: .blue], range: linkRange) 
return finalString 
}

上面function中的output是：您好，您可以撥打88 22 333號碼尋求進一步幫助

並使數字可點擊，我嘗試使用此屬性文本輸入到 UITextView 並啟用 dataDetectorType 屬性，但它對我不起作用:(有什么方法可以通過 UILabel 本身或任何類型的 UIKit 元素實現它，任何建議都是非常感謝，謝謝

我已經嘗試在啟用了 dataDetectorType 屬性的情況下使用此屬性文本輸入到 UITextView，但它對我不起作用:( 有什么方法可以使 UILabel 本身或任何類型的 UIKit 元素發生這種情況，提前非常感謝任何建議，謝謝

Answer 1

首先，您需要在全球范圍內申報手機號碼。

var mobileNo = "88 22 333"

為您的文本設置屬性字符串並創建可點擊的 label。

func setupLabel() {
    
    let fullString = "Hey you can dial up " + mobileNo + " number for further assistance"
    let strNSString: NSString = fullString as NSString
    let rangeNumber = (strNSString).range(of: mobileNo)
    let attribute = NSMutableAttributedString.init(string: fullString)
    attribute.addAttribute(NSAttributedString.Key.foregroundColor, value: UIColor.lightGray , range: rangeNumber)
    attribute.addAttribute(NSAttributedString.Key.font, value: UIFont.systemFont(ofSize: 16), range: rangeNumber)
    lblNumber.attributedText = attribute
    
    //Tap Gesture
    let tapGesture = UITapGestureRecognizer(target: self, action: #selector(lblNumberTapped))
    lblNumber.addGestureRecognizer(tapGesture)
    lblNumber.isUserInteractionEnabled = true
}

之后聲明點擊手勢的方法。

//MARK: - TapGesture Click events
@objc func lblNumberTapped(_ gesture: UITapGestureRecognizer) {
    self.view.endEditing(true)
    
    let text = self.lblNumber.text ?? ""
    let recoverMobileNumber = (text as NSString).range(of: mobileNo)

    if gesture.didTapAttributedTextInLabel(label: lblNumber, inRange: recoverMobileNumber) {
        if let callUrl = URL(string: "tel://\(mobileNo)"), UIApplication.shared.canOpenURL(callUrl) {
             UIApplication.shared.open(callUrl)
        }

    }
    

}

您需要 UITapGestureRecognizer 擴展來檢測點擊事件。

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 textBoundingBox = layoutManager.boundingRect(forGlyphRange: targetRange, in: 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)
}
}