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
我很难处理这件事…带有链接的UILabel在带属性的文本上…这只是一个头痛,所以我最终使用ZSWTappableLabel。
其他回答
这里是一个Swift实现,它是尽可能少的,还包括触摸反馈。警告:
你必须在NSAttributedStrings中设置字体 你只能使用NSAttributedStrings! 你必须确保你的链接不能自动换行(使用不间断的空格:"\u{a0}") 设置文本后,不能更改lineBreakMode或numberolines 通过添加带有.link键的属性来创建链接
.
public class LinkLabel: UILabel {
private var storage: NSTextStorage?
private let textContainer = NSTextContainer()
private let layoutManager = NSLayoutManager()
private var selectedBackgroundView = UIView()
override init(frame: CGRect) {
super.init(frame: frame)
textContainer.lineFragmentPadding = 0
layoutManager.addTextContainer(textContainer)
textContainer.layoutManager = layoutManager
isUserInteractionEnabled = true
selectedBackgroundView.isHidden = true
selectedBackgroundView.backgroundColor = UIColor(white: 0, alpha: 0.3333)
selectedBackgroundView.layer.cornerRadius = 4
addSubview(selectedBackgroundView)
}
public required convenience init(coder: NSCoder) {
self.init(frame: .zero)
}
public override func layoutSubviews() {
super.layoutSubviews()
textContainer.size = frame.size
}
public override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) {
super.touchesBegan(touches, with: event)
setLink(for: touches)
}
public override func touchesMoved(_ touches: Set<UITouch>, with event: UIEvent?) {
super.touchesMoved(touches, with: event)
setLink(for: touches)
}
private func setLink(for touches: Set<UITouch>) {
if let pt = touches.first?.location(in: self), let (characterRange, _) = link(at: pt) {
let glyphRange = layoutManager.glyphRange(forCharacterRange: characterRange, actualCharacterRange: nil)
selectedBackgroundView.frame = layoutManager.boundingRect(forGlyphRange: glyphRange, in: textContainer).insetBy(dx: -3, dy: -3)
selectedBackgroundView.isHidden = false
} else {
selectedBackgroundView.isHidden = true
}
}
public override func touchesCancelled(_ touches: Set<UITouch>, with event: UIEvent?) {
super.touchesCancelled(touches, with: event)
selectedBackgroundView.isHidden = true
}
public override func touchesEnded(_ touches: Set<UITouch>, with event: UIEvent?) {
super.touchesEnded(touches, with: event)
selectedBackgroundView.isHidden = true
if let pt = touches.first?.location(in: self), let (_, url) = link(at: pt) {
UIApplication.shared.open(url)
}
}
private func link(at point: CGPoint) -> (NSRange, URL)? {
let touchedGlyph = layoutManager.glyphIndex(for: point, in: textContainer)
let touchedChar = layoutManager.characterIndexForGlyph(at: touchedGlyph)
var range = NSRange()
let attrs = attributedText!.attributes(at: touchedChar, effectiveRange: &range)
if let urlstr = attrs[.link] as? String {
return (range, URL(string: urlstr)!)
} else {
return nil
}
}
public override var attributedText: NSAttributedString? {
didSet {
textContainer.maximumNumberOfLines = numberOfLines
textContainer.lineBreakMode = lineBreakMode
if let txt = attributedText {
storage = NSTextStorage(attributedString: txt)
storage!.addLayoutManager(layoutManager)
layoutManager.textStorage = storage
textContainer.size = frame.size
}
}
}
}
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;
}
}
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()
}
}
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。
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。
推荐文章
- 如何删除默认的导航栏空间在SwiftUI导航视图
- 如何在iOS中使用Swift编程segue
- Swift -整数转换为小时/分钟/秒
- Swift:声明一个空字典
- 我如何用javascript编程点击链接?
- 在成功提交我的应用程序后,“太多符号文件”
- 首先添加一个UIView,甚至是导航栏
- 我如何改变UIButton标题颜色?
- 在Swift中如何调用GCD主线程上的参数方法?
- NSLayoutConstraints是可动画的吗?
- iOS -构建失败,CocoaPods无法找到头文件
- CFNetwork SSLHandshake iOS 9失败
- 请求失败:不可接受的内容类型:文本/html使用AFNetworking 2.0
- 缺少推荐的图标文件-该包不包含iPhone / iPod Touch的应用程序图标,像素为“120x120”,png格式
- 以编程方式创建segue