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

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。

其他回答

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;
    }
}

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

在Swift 3中工作,将整个代码粘贴在这里

    //****Make sure the textview 'Selectable' = checked, and 'Editable = Unchecked'

import UIKit

class ViewController: UIViewController, UITextViewDelegate {

    @IBOutlet var theNewTextView: UITextView!
    override func viewDidLoad() {
        super.viewDidLoad()

        //****textview = Selectable = checked, and Editable = Unchecked

        theNewTextView.delegate = self

        let theString = NSMutableAttributedString(string: "Agree to Terms")
        let theRange = theString.mutableString.range(of: "Terms")

        theString.addAttribute(NSLinkAttributeName, value: "ContactUs://", range: theRange)

        let theAttribute = [NSForegroundColorAttributeName: UIColor.blue, NSUnderlineStyleAttributeName: NSUnderlineStyle.styleSingle.rawValue] as [String : Any]

        theNewTextView.linkTextAttributes = theAttribute

     theNewTextView.attributedText = theString             

theString.setAttributes(theAttribute, range: theRange)

    }

    func textView(_ textView: UITextView, shouldInteractWith URL: URL, in characterRange: NSRange, interaction: UITextItemInteraction) -> Bool {

        if (URL.scheme?.hasPrefix("ContactUs://"))! {

            return false //interaction not allowed
        }

        //*** Set storyboard id same as VC name
        self.navigationController!.pushViewController((self.storyboard?.instantiateViewController(withIdentifier: "TheLastViewController"))! as UIViewController, animated: true)

        return true
    }

}

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。

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];
}