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

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;
    }
}

其他回答

我强烈建议使用自动检测文本中的url并将其转换为链接的库。 试一试:

TTTAttributedLabel (pod) ZSWTappableLabel (under).

两者都得到了麻省理工学院的许可。

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。

从iOS 15开始,SwiftUI内置支持Markdown标记语言,因此Markdown中的文本:

Text("You can [click this link](https://www.example.com) to visit the website.")

或者作为一个使用SwiftUI的最简单的例子,你可以这样做:

        HStack() {
            Text("Open the")
                .foregroundColor(.black)
            Link(destination: URL(string: "https://www.example.com/TOS.html")!) {
                Text("link")
                    .foregroundColor(.blue)
                    .underline()
            }
            Text("in browser")
                .foregroundColor(.black)
        }

是的,这是可能的,尽管一开始很困惑。我将进一步向您展示如何甚至可以单击文本中的任何区域。

使用这个方法,你可以有一个UI标签,如下所示:

多行友好 Autoshrink友好 可点击友好型(是的,甚至是单个角色) 斯威夫特5

步骤1:

使UILabel具有'Truncate Tail'的换行属性,并设置最小字体比例。

如果你不熟悉字体比例,请记住以下规则:

minimumFontSize/defaultFontSize = fontscale

在我的例子中,我希望7.2是最小字体大小,而我的起始字体大小是36。因此7.2 / 36 = 0.2

步骤2:

如果你不关心标签是可点击的,只是想要一个工作多行标签你就完成了!

然而,如果你想要标签是可点击阅读…

添加以下扩展我创建

extension UILabel {

    func setOptimalFontSize(maxFontSize:CGFloat,text:String){
        let width = self.bounds.size.width

        var font_size:CGFloat = maxFontSize //Set the maximum font size.
        var stringSize = NSString(string: text).size(withAttributes: [.font : self.font.withSize(font_size)])
        while(stringSize.width > width){
            font_size = font_size - 1
            stringSize = NSString(string: text).size(withAttributes: [.font : self.font.withSize(font_size)])
        }

        self.font = self.font.withSize(font_size)//Forcefully change font to match what it would be graphically.
    }
}

它的用法是这样的(只需将<Label>替换为您实际的标签名):

<Label>.setOptimalFontSize(maxFontSize: 36.0, text: formula)

这个扩展是需要的,因为自动收缩不会改变标签的'字体'属性后,它自动收缩,所以你必须通过计算它通过使用.size(withAttributes)函数模拟它的大小将与特定的字体。

这是必要的,因为检测在标签上单击的位置的解决方案需要知道确切的字体大小。

步骤3:

添加以下扩展名:

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 mutableAttribString = NSMutableAttributedString(attributedString: label.attributedText!)
        mutableAttribString.addAttributes([NSAttributedString.Key.font: label.font!], range: NSRange(location: 0, length: label.attributedText!.length))

        let paragraphStyle = NSMutableParagraphStyle()
        paragraphStyle.lineSpacing = 6
        paragraphStyle.lineBreakMode = .byTruncatingTail
        paragraphStyle.alignment = .center
        mutableAttribString.addAttributes([.paragraphStyle: paragraphStyle], range: NSMakeRange(0, mutableAttribString.string.count))

        let textStorage = NSTextStorage(attributedString: mutableAttribString)

        // Configure textContainer
        textContainer.lineFragmentPadding = 0.0
        textContainer.lineBreakMode = label.lineBreakMode
        textContainer.maximumNumberOfLines = label.numberOfLines

        // Configure layoutManager and textStorage
        layoutManager.addTextContainer(textContainer)

        textStorage.addLayoutManager(layoutManager)

        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 = CGPointMake((labelSize.width - textBoundingBox.size.width) * 0.5 - textBoundingBox.origin.x,
                                              //(labelSize.height - textBoundingBox.size.height) * 0.5 - textBoundingBox.origin.y);
        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 = CGPointMake(locationOfTouchInLabel.x - textContainerOffset.x,
                                                        // locationOfTouchInLabel.y - textContainerOffset.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=",indexOfCharacter)

        print("TargetRange=",targetRange)
        return NSLocationInRange(indexOfCharacter, targetRange)
    }

}

您将需要修改这个扩展为您的特定多行情况。在我的例子中,您将注意到我使用了段落样式。

let paragraphStyle = NSMutableParagraphStyle()
        paragraphStyle.lineSpacing = 6
        paragraphStyle.lineBreakMode = .byTruncatingTail
        paragraphStyle.alignment = .center
        mutableAttribString.addAttributes([.paragraphStyle: paragraphStyle], range: NSMakeRange(0, mutableAttribString.string.count))

确保在扩展中将此更改为您实际使用的行间距,以便一切计算正确。

步骤4:

添加gestureRecognizer到标签在viewDidLoad或你认为合适的地方,就像这样(只需替换< label >与你的标签名再次:

<Label>.addGestureRecognizer(UITapGestureRecognizer(target:self, action: #selector(tapLabel(gesture:))))

这是我的tapLabel函数的一个简化示例(只需将<Label>替换为您的UILabel名称):

@IBAction func tapLabel(gesture: UITapGestureRecognizer) {
        guard let text = <Label>.attributedText?.string else {
            return
        }

        let click_range = text.range(of: "(α/β)")

        if gesture.didTapAttributedTextInLabel(label: <Label>, inRange: NSRange(click_range!, in: text)) {
           print("Tapped a/b")
        }else {
           print("Tapped none")
        }
    }

在我的例子中,我的字符串是BED = N * d * [RBE + (d / (α/β))],所以我只是在这种情况下得到α/β的范围。您可以在字符串中添加“\n”以添加换行符和任何您想要的文本,并测试此以在下一行中找到字符串,它仍然会找到它并正确地检测点击!

就是这样!你完成了。享受多行可点击标签。

用下面的.h和.m文件创建类。在.m文件中有以下函数

 - (void)linkAtPoint:(CGPoint)location

在这个函数中,我们将检查需要给予操作的子字符串的范围。使用你自己的逻辑来设置你的范围。

下面是子类的用法

TaggedLabel *label = [[TaggedLabel alloc] initWithFrame:CGRectMake(100, 100, 100, 100)];
[self.view addSubview:label];
label.numberOfLines = 0;
NSMutableAttributedString *attributtedString = [[NSMutableAttributedString alloc] initWithString : @"My name is @jjpp" attributes : @{ NSFontAttributeName : [UIFont systemFontOfSize:10],}];                                                                                                                                                                              
//Do not forget to add the font attribute.. else it wont work.. it is very important
[attributtedString addAttribute:NSForegroundColorAttributeName
                        value:[UIColor redColor]
                        range:NSMakeRange(11, 5)];//you can give this range inside the .m function mentioned above

下面是.h文件

#import <UIKit/UIKit.h>

@interface TaggedLabel : UILabel<NSLayoutManagerDelegate>

@property(nonatomic, strong)NSLayoutManager *layoutManager;
@property(nonatomic, strong)NSTextContainer *textContainer;
@property(nonatomic, strong)NSTextStorage *textStorage;
@property(nonatomic, strong)NSArray *tagsArray;
@property(readwrite, copy) tagTapped nameTagTapped;

@end   

下面是.m文件

#import "TaggedLabel.h"
@implementation TaggedLabel

- (id)initWithFrame:(CGRect)frame
{
 self = [super initWithFrame:frame];
 if (self)
 {
  self.userInteractionEnabled = YES;
 }
return self;
}

- (id)initWithCoder:(NSCoder *)aDecoder
{
 self = [super initWithCoder:aDecoder];
if (self)
{
 self.userInteractionEnabled = YES;
}
return self;
}

- (void)setupTextSystem
{
 _layoutManager = [[NSLayoutManager alloc] init];
 _textContainer = [[NSTextContainer alloc] initWithSize:CGSizeZero];
 _textStorage = [[NSTextStorage alloc] initWithAttributedString:self.attributedText];
 // Configure layoutManager and textStorage
 [_layoutManager addTextContainer:_textContainer];
 [_textStorage addLayoutManager:_layoutManager];
 // Configure textContainer
 _textContainer.lineFragmentPadding = 0.0;
 _textContainer.lineBreakMode = NSLineBreakByWordWrapping;
 _textContainer.maximumNumberOfLines = 0;
 self.userInteractionEnabled = YES;
 self.textContainer.size = self.bounds.size;
}

- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
{
 if (!_layoutManager)
 {
  [self setupTextSystem];
 }
 // Get the info for the touched link if there is one
 CGPoint touchLocation = [[touches anyObject] locationInView:self];
 [self linkAtPoint:touchLocation];
}

- (void)linkAtPoint:(CGPoint)location
{
 // Do nothing if we have no text
 if (_textStorage.string.length == 0)
 {
  return;
 }
 // Work out the offset of the text in the view
 CGPoint textOffset = [self calcGlyphsPositionInView];
 // Get the touch location and use text offset to convert to text cotainer coords
 location.x -= textOffset.x;
 location.y -= textOffset.y;
 NSUInteger touchedChar = [_layoutManager glyphIndexForPoint:location inTextContainer:_textContainer];
 // If the touch is in white space after the last glyph on the line we don't
 // count it as a hit on the text
 NSRange lineRange;
 CGRect lineRect = [_layoutManager lineFragmentUsedRectForGlyphAtIndex:touchedChar effectiveRange:&lineRange];
 if (CGRectContainsPoint(lineRect, location) == NO)
 {
  return;
 }
 // Find the word that was touched and call the detection block
    NSRange range = NSMakeRange(11, 5);//for this example i'm hardcoding the range here. In a real scenario it should be iterated through an array for checking all the ranges
    if ((touchedChar >= range.location) && touchedChar < (range.location + range.length))
    {
     NSLog(@"range-->>%@",self.tagsArray[i][@"range"]);
    }
}

- (CGPoint)calcGlyphsPositionInView
{
 CGPoint textOffset = CGPointZero;
 CGRect textBounds = [_layoutManager usedRectForTextContainer:_textContainer];
 textBounds.size.width = ceil(textBounds.size.width);
 textBounds.size.height = ceil(textBounds.size.height);

 if (textBounds.size.height < self.bounds.size.height)
 {
  CGFloat paddingHeight = (self.bounds.size.height - textBounds.size.height) / 2.0;
  textOffset.y = paddingHeight;
 }

 if (textBounds.size.width < self.bounds.size.width)
 {
  CGFloat paddingHeight = (self.bounds.size.width - textBounds.size.width) / 2.0;
  textOffset.x = paddingHeight;
 }
 return textOffset;
 }

@end