标签# Swift2.0

我从- excellent - @NAlexN的回答中获得灵感，我决定自己写一个UILabel的包装器。 我还尝试了TTTAttributedLabel，但我不能使它工作。

希望你能欣赏这段代码，欢迎任何建议!

import Foundation

@objc protocol TappableLabelDelegate {
    optional func tappableLabel(tabbableLabel: TappableLabel, didTapUrl: NSURL, atRange: NSRange)
}

/// Represent a label with attributed text inside.
/// We can add a correspondence between a range of the attributed string an a link (URL)
/// By default, link will be open on the external browser @see 'openLinkOnExternalBrowser'

class TappableLabel: UILabel {

    // MARK: - Public properties -

    var links: NSMutableDictionary = [:]
    var openLinkOnExternalBrowser = true
    var delegate: TappableLabelDelegate?

    // MARK: - Constructors -

    override func awakeFromNib() {
        super.awakeFromNib()
        self.enableInteraction()
    }

    override init(frame: CGRect) {
        super.init(frame: frame)
        self.enableInteraction()
    }

    required init?(coder aDecoder: NSCoder) {
        super.init(coder: aDecoder)
    }

    private func enableInteraction() {
        self.userInteractionEnabled = true
        self.addGestureRecognizer(UITapGestureRecognizer(target: self, action: Selector("didTapOnLabel:")))
    }

    // MARK: - Public methods -

    /**
    Add correspondence between a range and a link.

    - parameter url:   url.
    - parameter range: range on which couple url.
    */
    func addLink(url url: String, atRange range: NSRange) {
        self.links[url] = range
    }

    // MARK: - Public properties -

    /**
    Action rised on user interaction on label.

    - parameter tapGesture: gesture.
    */
    func didTapOnLabel(tapGesture: UITapGestureRecognizer) {
        let labelSize = self.bounds.size;

        let layoutManager = NSLayoutManager()
        let textContainer = NSTextContainer(size: CGSizeZero)
        let textStorage = NSTextStorage(attributedString: self.attributedText!)

        // configure textContainer for the label
        textContainer.lineFragmentPadding = 0
        textContainer.lineBreakMode = self.lineBreakMode
        textContainer.maximumNumberOfLines = self.numberOfLines
        textContainer.size = labelSize;

        // configure layoutManager and textStorage
        layoutManager.addTextContainer(textContainer)
        textStorage.addLayoutManager(layoutManager)

        // find the tapped character location and compare it to the specified range
        let locationOfTouchInLabel = tapGesture.locationInView(self)

        let textBoundingBox = layoutManager.usedRectForTextContainer(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 locationOfTouchInTextContainer = CGPointMake(locationOfTouchInLabel.x - textContainerOffset.x,
            locationOfTouchInLabel.y - textContainerOffset.y)
        let indexOfCharacter = layoutManager.characterIndexForPoint(locationOfTouchInTextContainer,
            inTextContainer:textContainer,
            fractionOfDistanceBetweenInsertionPoints: nil)

        for (url, value) in self.links {
            if let range = value as? NSRange {
                if NSLocationInRange(indexOfCharacter, range) {
                    let url = NSURL(string: url as! String)!
                    if self.openLinkOnExternalBrowser {
                        UIApplication.sharedApplication().openURL(url)
                    }
                    self.delegate?.tappableLabel?(self, didTapUrl: url, atRange: range)
                }
            }
        }
    }

}

- (BOOL)didTapAttributedTextInLabel:(UILabel *)label inRange:(NSRange)targetRange{
    NSLayoutManager *layoutManager = [NSLayoutManager new];
    NSTextContainer *textContainer = [[NSTextContainer alloc] initWithSize:CGSizeZero];
    NSTextStorage *textStorage = [[NSTextStorage alloc] initWithAttributedString:label.attributedText];

    [layoutManager addTextContainer:textContainer];
    [textStorage addLayoutManager:layoutManager];

    textContainer.lineFragmentPadding = 0.0;
    textContainer.lineBreakMode = label.lineBreakMode;
    textContainer.maximumNumberOfLines = label.numberOfLines;
    CGSize labelSize = label.bounds.size;
    textContainer.size = labelSize;

    CGPoint locationOfTouchInLabel = [self locationInView:label];
    CGRect textBoundingBox = [layoutManager usedRectForTextContainer:textContainer];
    CGPoint textContainerOffset = CGPointMake((labelSize.width - textBoundingBox.size.width) * 0.5 - textBoundingBox.origin.x,
                                              (labelSize.height - textBoundingBox.size.height) * 0.5 - textBoundingBox.origin.y);
    CGPoint locationOfTouchInTextContainer = CGPointMake(locationOfTouchInLabel.x - textContainerOffset.x,
                                                         locationOfTouchInLabel.y - textContainerOffset.y);
    NSUInteger indexOfCharacter =[layoutManager characterIndexForPoint:locationOfTouchInTextContainer inTextContainer:textContainer fractionOfDistanceBetweenInsertionPoints:nil];

    return NSLocationInRange(indexOfCharacter, targetRange);
}

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];
}

有些答案并不如我所料。这是Swift解决方案，也支持textAlignment和多行。不需要子类化，只是这个UITapGestureRecognizer扩展:

import UIKit


extension UITapGestureRecognizer {
    
    func didTapAttributedString(_ string: String, in label: UILabel) -> Bool {
        
        guard let text = label.text else {
            
            return false
        }
        
        let range = (text as NSString).range(of: string)
        return self.didTapAttributedText(label: label, inRange: range)
    }
    
    private func didTapAttributedText(label: UILabel, inRange targetRange: NSRange) -> Bool {
        
        guard let attributedText = label.attributedText else {
            
            assertionFailure("attributedText must be set")
            return false
        }
        
        let textContainer = createTextContainer(for: label)
        
        let layoutManager = NSLayoutManager()
        layoutManager.addTextContainer(textContainer)
        
        let textStorage = NSTextStorage(attributedString: attributedText)
        if let font = label.font {
            
            textStorage.addAttribute(NSAttributedString.Key.font, value: font, range: NSMakeRange(0, attributedText.length))
        }
        textStorage.addLayoutManager(layoutManager)
        
        let locationOfTouchInLabel = location(in: label)
        let textBoundingBox = layoutManager.usedRect(for: textContainer)
        let alignmentOffset = aligmentOffset(for: label)
        
        let xOffset = ((label.bounds.size.width - textBoundingBox.size.width) * alignmentOffset) - textBoundingBox.origin.x
        let yOffset = ((label.bounds.size.height - textBoundingBox.size.height) * alignmentOffset) - textBoundingBox.origin.y
        let locationOfTouchInTextContainer = CGPoint(x: locationOfTouchInLabel.x - xOffset, y: locationOfTouchInLabel.y - yOffset)
        
        let characterTapped = layoutManager.characterIndex(for: locationOfTouchInTextContainer, in: textContainer, fractionOfDistanceBetweenInsertionPoints: nil)
        
        let lineTapped = Int(ceil(locationOfTouchInLabel.y / label.font.lineHeight)) - 1
        let rightMostPointInLineTapped = CGPoint(x: label.bounds.size.width, y: label.font.lineHeight * CGFloat(lineTapped))
        let charsInLineTapped = layoutManager.characterIndex(for: rightMostPointInLineTapped, in: textContainer, fractionOfDistanceBetweenInsertionPoints: nil)
        
        return characterTapped < charsInLineTapped ? targetRange.contains(characterTapped) : false
    }
    
    private func createTextContainer(for label: UILabel) -> NSTextContainer {
        
        let textContainer = NSTextContainer(size: label.bounds.size)
        textContainer.lineFragmentPadding = 0.0
        textContainer.lineBreakMode = label.lineBreakMode
        textContainer.maximumNumberOfLines = label.numberOfLines
        return textContainer
    }
    
    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
        }
    }
}

用法:

class ViewController: UIViewController {
    
    @IBOutlet var label : UILabel!
    
    let selectableString1 = "consectetur"
    let selectableString2 = "cupidatat"
    
    override func viewDidLoad() {
        super.viewDidLoad()
        
        let text = "Lorem ipsum dolor sit amet, \(selectableString1) adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat \(selectableString2) non proident, sunt in culpa qui officia deserunt mollit anim id est laborum."
        label.attributedText = NSMutableAttributedString(attributedString: NSAttributedString(string: text))
        
        let tapGesture = UITapGestureRecognizer(target: self, action: #selector(labelTapped))
        label.addGestureRecognizer(tapGesture)
        label.isUserInteractionEnabled = true
    }
    
    @objc func labelTapped(gesture: UITapGestureRecognizer) {
        
        if gesture.didTapAttributedString(selectableString1, in: label) {
            
            print("\(selectableString1) tapped")
        } else if gesture.didTapAttributedString(selectableString2, in: label) {
            
            print("\(selectableString2) tapped")
        } else {
            
            print("Text tapped")
        }
    }
}

Drop-in解决方案作为UILabel上的一个类别(这假设你的UILabel使用一个带有NSLinkAttributeName属性的带属性字符串):

@implementation UILabel (Support)

- (BOOL)openTappedLinkAtLocation:(CGPoint)location {
  CGSize labelSize = self.bounds.size;

  NSTextContainer* textContainer = [[NSTextContainer alloc] initWithSize:CGSizeZero];
  textContainer.lineFragmentPadding = 0.0;
  textContainer.lineBreakMode = self.lineBreakMode;
  textContainer.maximumNumberOfLines = self.numberOfLines;
  textContainer.size = labelSize;

  NSLayoutManager* layoutManager = [[NSLayoutManager alloc] init];
  [layoutManager addTextContainer:textContainer];

  NSTextStorage* textStorage = [[NSTextStorage alloc] initWithAttributedString:self.attributedText];
  [textStorage addAttribute:NSFontAttributeName value:self.font range:NSMakeRange(0, textStorage.length)];
  [textStorage addLayoutManager:layoutManager];

  CGRect textBoundingBox = [layoutManager usedRectForTextContainer:textContainer];
  CGPoint textContainerOffset = CGPointMake((labelSize.width - textBoundingBox.size.width) * 0.5 - textBoundingBox.origin.x,
                                            (labelSize.height - textBoundingBox.size.height) * 0.5 - textBoundingBox.origin.y);
  CGPoint locationOfTouchInTextContainer = CGPointMake(location.x - textContainerOffset.x, location.y - textContainerOffset.y);
  NSInteger indexOfCharacter = [layoutManager characterIndexForPoint:locationOfTouchInTextContainer inTextContainer:textContainer fractionOfDistanceBetweenInsertionPoints:nullptr];
  if (indexOfCharacter >= 0) {
    NSURL* url = [textStorage attribute:NSLinkAttributeName atIndex:indexOfCharacter effectiveRange:nullptr];
    if (url) {
      [[UIApplication sharedApplication] openURL:url];
      return YES;
    }
  }
  return NO;
}

@end

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;
    }
}