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

以下是NAlexN的回答。

class TapabbleLabel: UILabel {

let layoutManager = NSLayoutManager()
let textContainer = NSTextContainer(size: CGSize.zero)
var textStorage = NSTextStorage() {
    didSet {
        textStorage.addLayoutManager(layoutManager)
    }
}

var onCharacterTapped: ((label: UILabel, characterIndex: Int) -> Void)?

let tapGesture = UITapGestureRecognizer()

override var attributedText: NSAttributedString? {
    didSet {
        if let attributedText = attributedText {
            textStorage = NSTextStorage(attributedString: attributedText)
        } else {
            textStorage = NSTextStorage()
        }
    }
}

override var lineBreakMode: NSLineBreakMode {
    didSet {
        textContainer.lineBreakMode = lineBreakMode
    }
}

override var numberOfLines: Int {
    didSet {
        textContainer.maximumNumberOfLines = numberOfLines
    }
}

/**
 Creates a new view with the passed coder.

 :param: aDecoder The a decoder

 :returns: the created new view.
 */
required init?(coder aDecoder: NSCoder) {
    super.init(coder: aDecoder)
    setUp()
}

/**
 Creates a new view with the passed frame.

 :param: frame The frame

 :returns: the created new view.
 */
override init(frame: CGRect) {
    super.init(frame: frame)
    setUp()
}

/**
 Sets up the view.
 */
func setUp() {
    userInteractionEnabled = true
    layoutManager.addTextContainer(textContainer)
    textContainer.lineFragmentPadding = 0
    textContainer.lineBreakMode = lineBreakMode
    textContainer.maximumNumberOfLines = numberOfLines
    tapGesture.addTarget(self, action: #selector(TapabbleLabel.labelTapped(_:)))
    addGestureRecognizer(tapGesture)
}

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

func labelTapped(gesture: UITapGestureRecognizer) {
    guard gesture.state == .Ended else {
        return
    }

    let locationOfTouch = gesture.locationInView(gesture.view)
    let textBoundingBox = layoutManager.usedRectForTextContainer(textContainer)
    let textContainerOffset = CGPoint(x: (bounds.width - textBoundingBox.width) / 2 - textBoundingBox.minX,
                                      y: (bounds.height - textBoundingBox.height) / 2 - textBoundingBox.minY)        
    let locationOfTouchInTextContainer = CGPoint(x: locationOfTouch.x - textContainerOffset.x,
                                                 y: locationOfTouch.y - textContainerOffset.y)
    let indexOfCharacter = layoutManager.characterIndexForPoint(locationOfTouchInTextContainer,
                                                                inTextContainer: textContainer,
                                                                fractionOfDistanceBetweenInsertionPoints: nil)

    onCharacterTapped?(label: self, characterIndex: indexOfCharacter)
}
}

然后你可以在你的viewDidLoad方法中创建一个类的实例,就像这样:

let label = TapabbleLabel()
label.translatesAutoresizingMaskIntoConstraints = false
view.addSubview(label)
view.addConstraints(NSLayoutConstraint.constraintsWithVisualFormat("V:|-[view]-|",
                                               options: [], metrics: nil, views: ["view" : label]))
view.addConstraints(NSLayoutConstraint.constraintsWithVisualFormat("H:|-[view]-|",
                                               options: [], metrics: nil, views: ["view" : label]))

let attributedString = NSMutableAttributedString(string: "String with a link", attributes: nil)
let linkRange = NSMakeRange(14, 4); // for the word "link" in the string above

let linkAttributes: [String : AnyObject] = [
    NSForegroundColorAttributeName : UIColor.blueColor(), NSUnderlineStyleAttributeName : NSUnderlineStyle.StyleSingle.rawValue,
    NSLinkAttributeName: "http://www.apple.com"]
attributedString.setAttributes(linkAttributes, range:linkRange)

label.attributedText = attributedString

label.onCharacterTapped = { label, characterIndex in
    if let attribute = label.attributedText?.attribute(NSLinkAttributeName, atIndex: characterIndex, effectiveRange: nil) as? String,
        let url = NSURL(string: attribute) {
        UIApplication.sharedApplication().openURL(url)
    }
}

最好有一个自定义属性,以便在点击字符时使用。它是NSLinkAttributeName,但可以是任何东西你可以使用那个值去做其他的事情除了打开一个url,你可以做任何自定义动作。

其他回答

UIButtonTypeCustom是一个可点击的标签,如果你没有为它设置任何图像。

我找到了另一个解决方案:

我找到了一种方法来检测你从互联网上找到的html文本链接,你把它转换成nsattributeString:

func htmlAttributedString(fontSize: CGFloat = 17.0) -> NSAttributedString? {
            let fontName = UIFont.systemFont(ofSize: fontSize).fontName
            let string = self.appending(String(format: "<style>body{font-family: '%@'; font-size:%fpx;}</style>", fontName, fontSize))
            guard let data = string.data(using: String.Encoding.utf16, allowLossyConversion: false) else { return nil }

            guard let html = try? NSMutableAttributedString (
                data: data,
                options: [NSAttributedString.DocumentReadingOptionKey.documentType: NSAttributedString.DocumentType.html],
                documentAttributes: nil) else { return nil }
            return html
        }

我的方法允许您检测超链接,而无需指定它们。

first you create an extension of the tapgesturerecognizer : extension UITapGestureRecognizer { func didTapAttributedTextInLabel(label: UILabel, inRange targetRange: NSRange) -> Bool { guard let attrString = label.attributedText else { return false } let layoutManager = NSLayoutManager() let textContainer = NSTextContainer(size: .zero) let textStorage = NSTextStorage(attributedString: attrString) layoutManager.addTextContainer(textContainer) textStorage.addLayoutManager(layoutManager) textContainer.lineFragmentPadding = 0 textContainer.lineBreakMode = label.lineBreakMode textContainer.maximumNumberOfLines = label.numberOfLines let labelSize = label.bounds.size textContainer.size = labelSize 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) } }

然后在你的视图控制器中,你创建了一个url和范围列表来存储属性文本包含的所有链接和范围:

var listurl : [String] = []
    var listURLRange : [NSRange] = []

找到URL和URLRange,你可以使用:

    fun findLinksAndRange(attributeString : NSAttributeString){
        notification.enumerateAttribute(NSAttributedStringKey.link , in: NSMakeRange(0, notification.length), options: [.longestEffectiveRangeNotRequired]) { value, range, isStop in
                    if let value = value {
                        print("\(value) found at \(range.location)")
                        let stringValue = "\(value)"
                        listurl.append(stringValue)
                        listURLRange.append(range)
                    }
                }

            westlandNotifcationLabel.addGestureRecognizer(UITapGestureRecognizer(target : self, action: #selector(handleTapOnLabel(_:))))

    }

然后你实现了手柄tap:

@objc func handleTapOnLabel(_ recognizer: UITapGestureRecognizer) {
        for index in 0..<listURLRange.count{
            if recognizer.didTapAttributedTextInLabel(label: westlandNotifcationLabel, inRange: listURLRange[index]) {
                goToWebsite(url : listurl[index])
            }
        }
    }

    func goToWebsite(url : String){
        if let websiteUrl = URL(string: url){
            if #available(iOS 10, *) {
                UIApplication.shared.open(websiteUrl, options: [:],
                                          completionHandler: {
                                            (success) in
                                            print("Open \(websiteUrl): \(success)")
                })
            } else {
                let success = UIApplication.shared.openURL(websiteUrl)
                print("Open \(websiteUrl): \(success)")
            }
        }
    }

开始了!

我希望这个解决方案能帮助你,就像它帮助我一样。

这是一个Objective-C类别,它支持现有UILabel中的可点击链接。attributedText字符串,利用现有的NSLinkAttributeName属性。

@interface UILabel (GSBClickableLinks) <UIGestureRecognizerDelegate>
@property BOOL enableLinks;
@end

#import <objc/runtime.h>
static const void *INDEX;
static const void *TAP;

@implementation UILabel (GSBClickableLinks)

- (void)setEnableLinks:(BOOL)enableLinks
{
    UITapGestureRecognizer *tap = objc_getAssociatedObject(self, &TAP); // retreive tap
    if (enableLinks && !tap) { // add a gestureRegonzier to the UILabel to detect taps
        tap = [UITapGestureRecognizer.alloc initWithTarget:self action:@selector(openLink)];
        tap.delegate = self;
        [self addGestureRecognizer:tap];
        objc_setAssociatedObject(self, &TAP, tap, OBJC_ASSOCIATION_RETAIN_NONATOMIC); // save tap
    }
    self.userInteractionEnabled = enableLinks; // note - when false UILAbel wont receive taps, hence disable links
}

- (BOOL)enableLinks
{
    return (BOOL)objc_getAssociatedObject(self, &TAP); // ie tap != nil
}

// First check whether user tapped on a link within the attributedText of the label.
// If so, then the our label's gestureRecogizer will subsequently fire, and open the corresponding NSLinkAttributeName.
// If not, then the tap will get passed along, eg to the enclosing UITableViewCell...
// Note: save which character in the attributedText was clicked so that we dont have to redo everything again in openLink.
- (BOOL)gestureRecognizerShouldBegin:(UIGestureRecognizer *)gestureRecognizer
{
    if (gestureRecognizer != objc_getAssociatedObject(self, &TAP)) return YES; // dont block other gestures (eg swipe)

    // Re-layout the attributedText to find out what was tapped
    NSTextContainer *textContainer = [NSTextContainer.alloc initWithSize:self.frame.size];
    textContainer.lineFragmentPadding = 0;
    textContainer.maximumNumberOfLines = self.numberOfLines;
    textContainer.lineBreakMode = self.lineBreakMode;
    NSLayoutManager *layoutManager = NSLayoutManager.new;
    [layoutManager addTextContainer:textContainer];
    NSTextStorage *textStorage = [NSTextStorage.alloc initWithAttributedString:self.attributedText];
    [textStorage addLayoutManager:layoutManager];

    NSUInteger index = [layoutManager characterIndexForPoint:[gestureRecognizer locationInView:self]
                                             inTextContainer:textContainer
                    fractionOfDistanceBetweenInsertionPoints:NULL];
    objc_setAssociatedObject(self, &INDEX, @(index), OBJC_ASSOCIATION_RETAIN_NONATOMIC); // save index

    return (BOOL)[self.attributedText attribute:NSLinkAttributeName atIndex:index effectiveRange:NULL]; // tapped on part of a link?
}

- (void)openLink
{
    NSUInteger index = [objc_getAssociatedObject(self, &INDEX) unsignedIntegerValue]; // retrieve index
    NSURL *url = [self.attributedText attribute:NSLinkAttributeName atIndex:index effectiveRange:NULL];
    if (url && [UIApplication.sharedApplication canOpenURL:url]) [UIApplication.sharedApplication openURL:url];
}

@end 

这将通过一个UILabel子类(即没有objc_getAssociatedObject的混乱)来完成,但如果你像我一样,你更喜欢避免不必要的(第三方)子类,只是为了给现有的UIKit类添加一些额外的功能。此外,这有一个漂亮的地方,它添加了任何现有的UILabel的点击链接,例如现有的UITableViewCells!

我已经试着让它尽可能的最小化侵入性通过使用现有的NSLinkAttributeName属性在NSAttributedString中已经可用。所以很简单:

NSURL *myURL = [NSURL URLWithString:@"http://www.google.com"];
NSMutableAttributedString *myString = [NSMutableAttributedString.alloc initWithString:@"This string has a clickable link: "];
[myString appendAttributedString:[NSAttributedString.alloc initWithString:@"click here" attributes:@{NSLinkAttributeName:myURL}]];
...
myLabel.attributedText = myString;
myLabel.enableLinks = YES; // yes, that's all! :-)

基本上,它通过添加一个UIGestureRecognizer到你的UILabel来工作。最难的工作是在gestureRecognizerShouldBegin:中完成的,它会重新布局attributedText字符串,以找出被点击的字符。如果这个字符是NSLinkAttributeName的一部分,那么手势识别器将随后触发,检索相应的URL(从NSLinkAttributeName值),并打开每个通常的[UIApplication。sharedApplication openURL:url进程。

注意:通过在gestureRecognizerShouldBegin:中执行所有这些操作,如果你没有碰巧点击标签中的链接,事件就会被传递。因此,例如,你的UITableViewCell将捕获点击链接,但其他行为正常(选择单元格,取消选择,滚动,…)。

我把它放在了GitHub仓库里。 改编自Kai Burghardt的SO帖子。

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
        }
    }

正如我在这篇文章中提到的, 这是我专门为UILabel FRHyperLabel中的链接创建的一个轻量级库。

为了达到这样的效果:

Lorem ipsum dolor sit amet, consectetur adipiscing elit。我想要的是一辆公平的车。南在一个盒子里。Maecenas ac without eu without port dictum nec vel tellus。

使用代码:

//Step 1: Define a normal attributed string for non-link texts
NSString *string = @"Lorem ipsum dolor sit amet, consectetur adipiscing elit. Pellentesque quis blandit eros, sit amet vehicula justo. Nam at urna neque. Maecenas ac sem eu sem porta dictum nec vel tellus.";
NSDictionary *attributes = @{NSFontAttributeName: [UIFont preferredFontForTextStyle:UIFontTextStyleHeadline]};

label.attributedText = [[NSAttributedString alloc]initWithString:string attributes:attributes];


//Step 2: Define a selection handler block
void(^handler)(FRHyperLabel *label, NSString *substring) = ^(FRHyperLabel *label, NSString *substring){
    NSLog(@"Selected: %@", substring);
};


//Step 3: Add link substrings
[label setLinksForSubstrings:@[@"Lorem", @"Pellentesque", @"blandit", @"Maecenas"] withLinkHandler:handler];