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
就像在前面的回答中报告的那样,UITextView能够处理链接上的触摸。这可以通过将文本的其他部分作为链接来轻松扩展。AttributedTextView库是一个UITextView子类,它使得处理这些非常容易。更多信息请参见:https://github.com/evermeer/AttributedTextView
你可以让文本的任何部分像这样交互(其中textView1是一个UITextView IBOutlet):
textView1.attributer =
"1. ".red
.append("This is the first test. ").green
.append("Click on ").black
.append("evict.nl").makeInteract { _ in
UIApplication.shared.open(URL(string: "http://evict.nl")!, options: [:], completionHandler: { completed in })
}.underline
.append(" for testing links. ").black
.append("Next test").underline.makeInteract { _ in
print("NEXT")
}
.all.font(UIFont(name: "SourceSansPro-Regular", size: 16))
.setLinkColor(UIColor.purple)
为了处理标签和提及,你可以使用这样的代码:
textView1.attributer = "@test: What #hashtags do we have in @evermeer #AtributedTextView library"
.matchHashtags.underline
.matchMentions
.makeInteract { link in
UIApplication.shared.open(URL(string: "https://twitter.com\(link.replacingOccurrences(of: "@", with: ""))")!, options: [:], completionHandler: { completed in })
}
其他回答
我创建了一个名为ResponsiveLabel的UILabel子类,它是基于ios7中引入的textkit API。它使用了NAlexN建议的相同方法。它提供了在文本中指定搜索模式的灵活性。可以指定应用于这些模式的样式,以及在敲击模式时要执行的操作。
//Detects email in text
NSString *emailRegexString = @"[A-Z0-9._%+-]+@[A-Z0-9.-]+\\.[A-Z]{2,4}";
NSError *error;
NSRegularExpression *regex = [[NSRegularExpression alloc]initWithPattern:emailRegexString options:0 error:&error];
PatternDescriptor *descriptor = [[PatternDescriptor alloc]initWithRegex:regex withSearchType:PatternSearchTypeAll withPatternAttributes:@{NSForegroundColorAttributeName:[UIColor redColor]}];
[self.customLabel enablePatternDetection:descriptor];
如果你想让一个字符串可点击,你可以这样做。这段代码将属性应用到字符串“text”的每个出现处。
PatternTapResponder tapResponder = ^(NSString *string) {
NSLog(@"tapped = %@",string);
};
[self.customLabel enableStringDetection:@"text" withAttributes:@{NSForegroundColorAttributeName:[UIColor redColor],
RLTapResponderAttributeName: tapResponder}];
一般来说,如果我们想在UILabel显示的文本中有一个可点击的链接,我们需要解决两个独立的任务:
更改部分文本的外观,使其看起来像链接 检测和处理链接上的触摸(打开URL是一个特殊情况)
第一个很简单。从ios6开始,UILabel支持显示带属性的字符串。你所需要做的就是创建并配置一个NSMutableAttributedString实例:
NSMutableAttributedString *attributedString = [[NSMutableAttributedString alloc] initWithString:@"String with a link" attributes:nil];
NSRange linkRange = NSMakeRange(14, 4); // for the word "link" in the string above
NSDictionary *linkAttributes = @{ NSForegroundColorAttributeName : [UIColor colorWithRed:0.05 green:0.4 blue:0.65 alpha:1.0],
NSUnderlineStyleAttributeName : @(NSUnderlineStyleSingle) };
[attributedString setAttributes:linkAttributes range:linkRange];
// Assign attributedText to UILabel
label.attributedText = attributedString;
就是这样!上面的代码使UILabel显示带有链接的String
现在我们应该检测这个链接上的触摸。其思想是捕获UILabel中的所有点击,并确定点击的位置是否足够接近链接。为了捕捉触摸,我们可以在标签中添加点击手势识别器。确保为标签启用userInteraction,默认情况下是关闭的:
label.userInteractionEnabled = YES;
[label addGestureRecognizer:[[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(handleTapOnLabel:)]];
现在最复杂的事情是:找出点击是否在显示链接的地方,而不是在标签的任何其他部分。如果我们有单行UILabel,这个任务可以通过硬编码链接显示的区域边界来相对容易地解决,但是让我们更优雅地解决这个问题,对于一般情况-多行UILabel,而不需要对链接布局有初步的了解。
其中一种方法是使用iOS 7中引入的Text Kit API功能:
// Create instances of NSLayoutManager, NSTextContainer and NSTextStorage
NSLayoutManager *layoutManager = [[NSLayoutManager alloc] init];
NSTextContainer *textContainer = [[NSTextContainer alloc] initWithSize:CGSizeZero];
NSTextStorage *textStorage = [[NSTextStorage alloc] initWithAttributedString:attributedString];
// Configure layoutManager and textStorage
[layoutManager addTextContainer:textContainer];
[textStorage addLayoutManager:layoutManager];
// Configure textContainer
textContainer.lineFragmentPadding = 0.0;
textContainer.lineBreakMode = label.lineBreakMode;
textContainer.maximumNumberOfLines = label.numberOfLines;
将创建和配置的NSLayoutManager, NSTextContainer和NSTextStorage实例保存在类的属性中(很可能是UIViewController的后代)-我们将在其他方法中需要它们。
现在,每当标签改变它的框架,更新textContainer的大小:
- (void)viewDidLayoutSubviews
{
[super viewDidLayoutSubviews];
self.textContainer.size = self.label.bounds.size;
}
最后,检测点击是否恰好在链接上:
- (void)handleTapOnLabel:(UITapGestureRecognizer *)tapGesture
{
CGPoint locationOfTouchInLabel = [tapGesture locationInView:tapGesture.view];
CGSize labelSize = tapGesture.view.bounds.size;
CGRect textBoundingBox = [self.layoutManager usedRectForTextContainer:self.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);
NSInteger indexOfCharacter = [self.layoutManager characterIndexForPoint:locationOfTouchInTextContainer
inTextContainer:self.textContainer
fractionOfDistanceBetweenInsertionPoints:nil];
NSRange linkRange = NSMakeRange(14, 4); // it's better to save the range somewhere when it was originally used for marking link in attributed string
if (NSLocationInRange(indexOfCharacter, linkRange)) {
// Open an URL, or handle the tap on the link in any other way
[[UIApplication sharedApplication] openURL:[NSURL URLWithString:@"https://stackoverflow.com/"]];
}
}
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];
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
}
}
UIButtonTypeCustom是一个可点击的标签,如果你没有为它设置任何图像。
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