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
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。
其他回答
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。
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()
}
}
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/"]];
}
}
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 })
}
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。
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