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

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

其他回答

这个通用方法也可以!

func didTapAttributedTextInLabel(gesture: UITapGestureRecognizer, inRange targetRange: NSRange) -> Bool {

        let layoutManager = NSLayoutManager()
        let textContainer = NSTextContainer(size: CGSize.zero)
        guard let strAttributedText = self.attributedText else {
            return false
        }

        let textStorage = NSTextStorage(attributedString: strAttributedText)

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

        // Configure textContainer
        textContainer.lineFragmentPadding = Constants.lineFragmentPadding
        textContainer.lineBreakMode = self.lineBreakMode
        textContainer.maximumNumberOfLines = self.numberOfLines
        let labelSize = self.bounds.size
        textContainer.size = CGSize(width: labelSize.width, height: CGFloat.greatestFiniteMagnitude)

        // Find the tapped character location and compare it to the specified range
        let locationOfTouchInLabel = gesture.location(in: self)

        let xCordLocationOfTouchInTextContainer = locationOfTouchInLabel.x
        let yCordLocationOfTouchInTextContainer = locationOfTouchInLabel.y
        let locOfTouch = CGPoint(x: xCordLocationOfTouchInTextContainer ,
                                 y: yCordLocationOfTouchInTextContainer)

        let indexOfCharacter = layoutManager.characterIndex(for: locOfTouch, in: textContainer, fractionOfDistanceBetweenInsertionPoints: nil)

        guard let strLabel = text else {
            return false
        }

        let charCountOfLabel = strLabel.count

        if indexOfCharacter < (charCountOfLabel - 1) {
            return NSLocationInRange(indexOfCharacter, targetRange)
        } else {
            return false
        }
    }

你可以用

let text = yourLabel.text
let termsRange = (text as NSString).range(of: fullString)
if yourLabel.didTapAttributedTextInLabel(gesture: UITapGestureRecognizer, inRange: termsRange) {
            showCorrespondingViewController()
        }

我遵循这个版本,

斯威夫特4:

import Foundation

class AELinkedClickableUILabel: UILabel {

    typealias YourCompletion = () -> Void

    var linkedRange: NSRange!
    var completion: YourCompletion?

    @objc func linkClicked(sender: UITapGestureRecognizer){

        if let completionBlock = completion {

            let textView = UITextView(frame: self.frame)
            textView.text = self.text
            textView.attributedText = self.attributedText
            let index = textView.layoutManager.characterIndex(for: sender.location(in: self),
                                                              in: textView.textContainer,
                                                              fractionOfDistanceBetweenInsertionPoints: nil)

            if linkedRange.lowerBound <= index && linkedRange.upperBound >= index {

                completionBlock()
            }
        }
    }

/**
 *  This method will be used to set an attributed text specifying the linked text with a
 *  handler when the link is clicked
 */
    public func setLinkedTextWithHandler(text:String, link: String, handler: @escaping ()->()) -> Bool {

        let attributextText = NSMutableAttributedString(string: text)
        let foundRange = attributextText.mutableString.range(of: link)

        if foundRange.location != NSNotFound {
            self.linkedRange = foundRange
            self.completion = handler
            attributextText.addAttribute(NSAttributedStringKey.link, value: text, range: foundRange)
            self.isUserInteractionEnabled = true
            self.addGestureRecognizer(UITapGestureRecognizer(target: self, action: #selector(linkClicked(sender:))))
            return true
        }
        return false
    }
}

电话的例子:

button.setLinkedTextWithHandler(text: "This website (stackoverflow.com) is awesome", link: "stackoverflow.com") 
{
    // show popup or open to link
}

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];

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];
}

对于完全自定义的链接,你需要使用UIWebView -你可以拦截调用,这样当链接被按下时,你可以转到应用程序的其他部分。