斯威夫特5.2

我在之前的回答中发现了多行文本标签的几个问题，所以我给出了我最终的工作解决方案。

它解决了多行和文本对齐的问题。

    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 textAligmentOffset = aligmentOffset(for: label)
        let textContainerOffset = CGPoint(x: (labelSize.width - textBoundingBox.size.width) * textAligmentOffset - textBoundingBox.origin.x,
                                          y: (labelSize.height - textBoundingBox.size.height) * textAligmentOffset - textBoundingBox.origin.y)
        let locationOfTouchInTextContainer = CGPoint(x: (locationOfTouchInLabel.x - textContainerOffset.x),
                                                     y: 0 )
        // Adjust for multiple lines of text
        let lineModifier = Int(floor(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)
        return NSLocationInRange(adjustedRange, targetRange)
    }
    
    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
        }
    }

这是沙玛林。基于Kedar的答案的iOS c#实现。

MyClickableTextViewWithCustomUrlScheme实现与ShouldInteractWithUrl覆盖:

// Inspired from https://stackoverflow.com/a/44112932/15186
internal class MyClickableTextViewWithCustomUrlScheme : UITextView, IUITextViewDelegate
{
    public MyClickableTextViewWithCustomUrlScheme()
    {
        Initialize();
    }

    public MyClickableTextViewWithCustomUrlScheme(Foundation.NSCoder coder) : base(coder)
    {
        Initialize();
    }

    public MyClickableTextViewWithCustomUrlScheme(Foundation.NSObjectFlag t) : base(t)
    {
        Initialize();
    }

    public MyClickableTextViewWithCustomUrlScheme(IntPtr handle) : base(handle)
    {
        Initialize();
    }

    public MyClickableTextViewWithCustomUrlScheme(CoreGraphics.CGRect frame) : base(frame)
    {
        Initialize();
    }

    public MyClickableTextViewWithCustomUrlScheme(CoreGraphics.CGRect frame, NSTextContainer textContainer) : base(frame, textContainer)
    {
        Initialize();
    }

    void Initialize()
    {
        Delegate = this;
    }

    [Export("textView:shouldInteractWithURL:inRange:")]
    public new bool ShouldInteractWithUrl(UITextView textView, NSUrl URL, NSRange characterRange)
    {
        if (URL.Scheme.CompareTo(@"username") == 0)
        {
            // Launch the Activity
            return false;
        }
        // The system will handle the URL
        return base.ShouldInteractWithUrl(textView, URL, characterRange);
    }
}

在c#中转换的objective-C代码变成:

MyClickableTextViewWithCustomUrlScheme uiHabitTile = new MyClickableTextViewWithCustomUrlScheme();
uiHabitTile.Selectable = true;
uiHabitTile.ScrollEnabled = false;
uiHabitTile.Editable = false;

// https://stackoverflow.com/a/34014655/15186
string wholeTitle = @"This is an example by marcelofabri";

NSMutableAttributedString attributedString = new NSMutableAttributedString(wholeTitle);
attributedString.AddAttribute(UIStringAttributeKey.Link,
   new NSString("username://marcelofabri"),
   attributedString.Value.RangeOfString(@"marcelofabri")
);
NSMutableDictionary<NSString, NSObject> linkAttributes = new NSMutableDictionary<NSString, NSObject>();
linkAttributes[UIStringAttributeKey.ForegroundColor] = UIColor.Green;
linkAttributes[UIStringAttributeKey.UnderlineColor] = UIColor.LightGray;
linkAttributes[UIStringAttributeKey.UnderlineStyle] = new NSNumber((short)NSUnderlineStyle.PatternSolid);

uiHabitTile.AttributedText = attributedString;

确保将Editable = false和Selectable = true设置为能够单击链接。

同样，ScrollEnabled = true允许textview正确地调整其高度大小。

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")
     }
    }

UITextView支持OS3.0中的数据检测器，而UILabel不支持。

如果你在UITextView上启用了数据检测器，并且你的文本包含url、电话号码等，它们将以链接的形式出现。

这里是一个Swift实现，它是尽可能少的，还包括触摸反馈。警告:

你必须在NSAttributedStrings中设置字体 你只能使用NSAttributedStrings! 你必须确保你的链接不能自动换行(使用不间断的空格:"\u{a0}") 设置文本后，不能更改lineBreakMode或numberolines 通过添加带有.link键的属性来创建链接

.

public class LinkLabel: UILabel {
    private var storage: NSTextStorage?
    private let textContainer = NSTextContainer()
    private let layoutManager = NSLayoutManager()
    private var selectedBackgroundView = UIView()

    override init(frame: CGRect) {
        super.init(frame: frame)
        textContainer.lineFragmentPadding = 0
        layoutManager.addTextContainer(textContainer)
        textContainer.layoutManager = layoutManager
        isUserInteractionEnabled = true
        selectedBackgroundView.isHidden = true
        selectedBackgroundView.backgroundColor = UIColor(white: 0, alpha: 0.3333)
        selectedBackgroundView.layer.cornerRadius = 4
        addSubview(selectedBackgroundView)
    }

    public required convenience init(coder: NSCoder) {
        self.init(frame: .zero)
    }

    public override func layoutSubviews() {
        super.layoutSubviews()
        textContainer.size = frame.size
    }

    public override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) {
        super.touchesBegan(touches, with: event)
        setLink(for: touches)
    }

    public override func touchesMoved(_ touches: Set<UITouch>, with event: UIEvent?) {
        super.touchesMoved(touches, with: event)
        setLink(for: touches)
    }

    private func setLink(for touches: Set<UITouch>) {
        if let pt = touches.first?.location(in: self), let (characterRange, _) = link(at: pt) {
            let glyphRange = layoutManager.glyphRange(forCharacterRange: characterRange, actualCharacterRange: nil)
            selectedBackgroundView.frame = layoutManager.boundingRect(forGlyphRange: glyphRange, in: textContainer).insetBy(dx: -3, dy: -3)
            selectedBackgroundView.isHidden = false
        } else {
            selectedBackgroundView.isHidden = true
        }
    }

    public override func touchesCancelled(_ touches: Set<UITouch>, with event: UIEvent?) {
        super.touchesCancelled(touches, with: event)
        selectedBackgroundView.isHidden = true
    }

    public override func touchesEnded(_ touches: Set<UITouch>, with event: UIEvent?) {
        super.touchesEnded(touches, with: event)
        selectedBackgroundView.isHidden = true

        if let pt = touches.first?.location(in: self), let (_, url) = link(at: pt) {
            UIApplication.shared.open(url)
        }
    }

    private func link(at point: CGPoint) -> (NSRange, URL)? {
        let touchedGlyph = layoutManager.glyphIndex(for: point, in: textContainer)
        let touchedChar = layoutManager.characterIndexForGlyph(at: touchedGlyph)
        var range = NSRange()
        let attrs = attributedText!.attributes(at: touchedChar, effectiveRange: &range)
        if let urlstr = attrs[.link] as? String {
            return (range, URL(string: urlstr)!)
        } else {
            return nil
        }
    }

    public override var attributedText: NSAttributedString? {
        didSet {
            textContainer.maximumNumberOfLines = numberOfLines
            textContainer.lineBreakMode = lineBreakMode
            if let txt = attributedText {
                storage = NSTextStorage(attributedString: txt)
                storage!.addLayoutManager(layoutManager)
                layoutManager.textStorage = storage
                textContainer.size = frame.size
            }
        }
    }
}

最简单可靠的方法是使用Kedar Paranjape推荐的UITextView。基于Karl Nosworthy的回答，我最终想出了一个简单的UITextView子类:

class LinkTextView: UITextView, UITextViewDelegate {
    
    typealias Links = [String: String]
    
    typealias OnLinkTap = (URL) -> Bool
    
    var onLinkTap: OnLinkTap?
    
    override init(frame: CGRect, textContainer: NSTextContainer?) {
        super.init(frame: frame, textContainer: textContainer)
        isEditable = false
        isSelectable = true
        isScrollEnabled = false //to have own size and behave like a label
        delegate = self
    }
    
    required init?(coder: NSCoder) {
        super.init(coder: coder)
    }
    
    func addLinks(_ links: Links) {
        guard attributedText.length > 0  else {
            return
        }
        let mText = NSMutableAttributedString(attributedString: attributedText)
        
        for (linkText, urlString) in links {
            if linkText.count > 0 {
                let linkRange = mText.mutableString.range(of: linkText)
                mText.addAttribute(.link, value: urlString, range: linkRange)
            }
        }
        attributedText = mText
    }
    
    func textView(_ textView: UITextView, shouldInteractWith URL: URL, in characterRange: NSRange) -> Bool {
        return onLinkTap?(URL) ?? true
    }
    
    // to disable text selection
    func textViewDidChangeSelection(_ textView: UITextView) {
        textView.selectedTextRange = nil
    }
}

用法非常简单:

    let linkTextView = LinkTextView()
    let tu = "Terms of Use"
    let pp = "Privacy Policy"
    linkTextView.text = "Please read the Some Company \(tu) and \(pp)"
    linkTextView.addLinks([
        tu: "https://some.com/tu",
        pp: "https://some.com/pp"
    ])
    linkTextView.onLinkTap = { url in
        print("url: \(url)")
        return true
    }

请注意，isScrollEnabled默认为false，因为在大多数情况下，我们需要有自己大小且没有滚动的类似标签的小视图。如果你想要一个可滚动的文本视图，就把它设为true。

还要注意，UITextView不像UILabel有默认的文本填充。要删除它，使布局与UILabel相同，只需添加:linkTextView。textContainerInset = . 0

实现onLinkTap闭包是不必要的，没有它url是由UIApplication自动打开的。

由于文本选择在大多数情况下是不可取的，但它不能关闭，它在委托方法中被解散(感谢Carson Vo)