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

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

其他回答

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)
        }

下面是超链接UILabel的示例代码: 来源:http://sickprogrammersarea.blogspot.in/2014/03/adding-links-to-uilabel.html

#import "ViewController.h"
#import "TTTAttributedLabel.h"

@interface ViewController ()
@end

@implementation ViewController
{
    UITextField *loc;
    TTTAttributedLabel *data;
}

- (void)viewDidLoad
{
    [super viewDidLoad];
    UILabel *lbl = [[UILabel alloc] initWithFrame:CGRectMake(5, 20, 80, 25) ];
    [lbl setText:@"Text:"];
    [lbl setFont:[UIFont fontWithName:@"Verdana" size:16]];
    [lbl setTextColor:[UIColor grayColor]];
    loc=[[UITextField alloc] initWithFrame:CGRectMake(4, 20, 300, 30)];
    //loc.backgroundColor = [UIColor grayColor];
    loc.borderStyle=UITextBorderStyleRoundedRect;
    loc.clearButtonMode=UITextFieldViewModeWhileEditing;
    //[loc setText:@"Enter Location"];
    loc.clearsOnInsertion = YES;
    loc.leftView=lbl;
    loc.leftViewMode=UITextFieldViewModeAlways;
    [loc setDelegate:self];
    [self.view addSubview:loc];
    [loc setRightViewMode:UITextFieldViewModeAlways];
    CGRect frameimg = CGRectMake(110, 70, 70,30);
    UIButton *srchButton = [UIButton buttonWithType:UIButtonTypeRoundedRect];
    srchButton.frame=frameimg;
    [srchButton setTitle:@"Go" forState:UIControlStateNormal];
    [srchButton setTitleColor:[UIColor blackColor] forState:UIControlStateNormal];
    srchButton.backgroundColor=[UIColor clearColor];
    [srchButton addTarget:self action:@selector(go:) forControlEvents:UIControlEventTouchDown];
    [self.view addSubview:srchButton];
    data = [[TTTAttributedLabel alloc] initWithFrame:CGRectMake(5, 120,self.view.frame.size.width,200) ];
    [data setFont:[UIFont fontWithName:@"Verdana" size:16]];
    [data setTextColor:[UIColor blackColor]];
    data.numberOfLines=0;
    data.delegate = self;
    data.enabledTextCheckingTypes=NSTextCheckingTypeLink|NSTextCheckingTypePhoneNumber;
    [self.view addSubview:data];
}
- (void)attributedLabel:(TTTAttributedLabel *)label didSelectLinkWithURL:(NSURL *)url
{
    NSString *val=[[NSString alloc]initWithFormat:@"%@",url];
    if ([[url scheme] hasPrefix:@"mailto"]) {
              NSLog(@" mail URL Selected : %@",url);
        MFMailComposeViewController *comp=[[MFMailComposeViewController alloc]init];
        [comp setMailComposeDelegate:self];
        if([MFMailComposeViewController canSendMail])
        {
            NSString *recp=[[val substringToIndex:[val length]] substringFromIndex:7];
            NSLog(@"Recept : %@",recp);
            [comp setToRecipients:[NSArray arrayWithObjects:recp, nil]];
            [comp setSubject:@"From my app"];
            [comp setMessageBody:@"Hello bro" isHTML:NO];
            [comp setModalTransitionStyle:UIModalTransitionStyleCrossDissolve];
            [self presentViewController:comp animated:YES completion:nil];
        }
    }
    else{
        [[UIApplication sharedApplication] openURL:[NSURL URLWithString:val]];
    }
}
-(void)mailComposeController:(MFMailComposeViewController *)controller didFinishWithResult:(MFMailComposeResult)result error:(NSError *)error{
    if(error)
    {
        UIAlertView *alrt=[[UIAlertView alloc]initWithTitle:@"Erorr" message:@"Some error occureed" delegate:nil cancelButtonTitle:@"" otherButtonTitles:nil, nil];
        [alrt show];
        [self dismissViewControllerAnimated:YES completion:nil];
    }
    else{
        [self dismissViewControllerAnimated:YES completion:nil];
    }
}

- (void)attributedLabel:(TTTAttributedLabel *)label didSelectLinkWithPhoneNumber:(NSString *)phoneNumber
{
    NSLog(@"Phone Number Selected : %@",phoneNumber);
    UIDevice *device = [UIDevice currentDevice];
    if ([[device model] isEqualToString:@"iPhone"] ) {
        [[UIApplication sharedApplication] openURL:[NSURL URLWithString:[NSString stringWithFormat:@"tel:%@",phoneNumber]]];
    } else {
        UIAlertView *Notpermitted=[[UIAlertView alloc] initWithTitle:@"Alert" message:@"Your device doesn't support this feature." delegate:nil cancelButtonTitle:@"OK" otherButtonTitles:nil];
        [Notpermitted show];
    }
}
-(void)go:(id)sender
{
    [data setText:loc.text];
}

-(void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
{
    NSLog(@"Reached");
    [loc resignFirstResponder];
}

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。

我们使用来自zekel的UITapGestureRecognizer类别的方便解决方案。 它使用了NSTextContainer,就像这个问题的许多答案一样。

但是,这将返回错误的字符索引。显然是因为NSTextContainer缺少关于字体样式的信息,正如这些其他帖子所指出的:

https://stackoverflow.com/a/34238382/2439941 https://stackoverflow.com/a/47358270/2439941

后改变:

NSTextStorage *textStorage = [[NSTextStorage alloc] initWithAttributedString:label.attributedText];

To:

// Apply the font of the label to the attributed text: 
NSMutableAttributedString *attributedText = [[NSMutableAttributedString alloc] initWithAttributedString:label.attributedText];
NSMutableParagraphStyle *paragraphStyle = NSMutableParagraphStyle.new;
paragraphStyle.alignment = self.label.textAlignment;
[attributedText addAttributes:@{NSFontAttributeName: label.font, NSParagraphStyleAttributeName: paragraphStyle} 
                        range:NSMakeRange(0, label.attributedText.string.length)];

// Init with attributed text from label:
NSTextStorage *textStorage = [[NSTextStorage alloc] initWithAttributedString:attributedText];

结果明显更好,点击区域现在正确地从目标字符串的第一个字符开始。但最后一个字符仍然返回NO。我们期望这与我们的目标字符串具有将字体权重设置为UIFontWeightSemibold的属性有关。而上面的代码改进应用标签。整个字符串上的字体,它有一个规则的权重。

为了解决这个问题,我们进一步改进了上面的代码片段,通过遍历所有属性范围,以支持文本中的多种字体样式:

// According to https://stackoverflow.com/a/47358270/2439941 it's required to apply the paragraph style and font of the UILabel.
// However, the attributed string might contain font formatting as well, e.g. to emphasize a word in a different font style.
// Therefor copy all attributes:
NSMutableAttributedString *attributedText = [[NSMutableAttributedString alloc] initWithAttributedString:label.attributedText];
[label.attributedText enumerateAttributesInRange:NSMakeRange(0, label.attributedText.length)
                                         options:0
                                      usingBlock:^(NSDictionary<NSAttributedStringKey,id> * _Nonnull attrs, NSRange range, BOOL * _Nonnull stop) {
    // Add each attribute:
    [attributedText addAttributes:attrs
                            range:range];
    
    // In case the attributes of this range do NOT contain a font specifier, apply the font from the UILabel:
    if (![attrs objectForKey:NSFontAttributeName]) {
        [attributedText addAttributes:@{ NSFontAttributeName : label.font }
                                range:range];
    }
}];

// Init the storage with the font attributed text:
NSTextStorage *textStorage = [[NSTextStorage alloc] initWithAttributedString:attributedText];

现在,该方法为半粗体字符串范围内的每个字符返回YES,这是预期的结果。

翻译@samwize的扩展到Swift 4:

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)
    }
}

要设置识别器(一旦你给文本和东西上色):

lblTermsOfUse.isUserInteractionEnabled = true
lblTermsOfUse.addGestureRecognizer(UITapGestureRecognizer(target: self, action: #selector(handleTapOnLabel(_:))))

...然后是手势识别器:

@objc func handleTapOnLabel(_ recognizer: UITapGestureRecognizer) {
    guard let text = lblAgreeToTerms.attributedText?.string else {
        return
    }

    if let range = text.range(of: NSLocalizedString("_onboarding_terms", comment: "terms")),
        recognizer.didTapAttributedTextInLabel(label: lblAgreeToTerms, inRange: NSRange(range, in: text)) {
        goToTermsAndConditions()
    } else if let range = text.range(of: NSLocalizedString("_onboarding_privacy", comment: "privacy")),
        recognizer.didTapAttributedTextInLabel(label: lblAgreeToTerms, inRange: NSRange(range, in: text)) {
        goToPrivacyPolicy()
    }
}