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
老问题,但如果任何人都可以使用UITextView而不是UILabel,那就很容易了。标准网址,电话号码等将自动检测(并可点击)。
然而,如果你需要自定义检测,也就是说,如果你想在用户点击一个特定的单词后能够调用任何自定义方法,你需要使用NSAttributedStrings和一个NSLinkAttributeName属性,它将指向一个自定义URL方案(而不是在默认情况下使用http URL方案)。雷·温德里奇在这里报道
引用上述链接中的代码:
NSMutableAttributedString *attributedString = [[NSMutableAttributedString alloc] initWithString:@"This is an example by @marcelofabri_"];
[attributedString addAttribute:NSLinkAttributeName
value:@"username://marcelofabri_"
range:[[attributedString string] rangeOfString:@"@marcelofabri_"]];
NSDictionary *linkAttributes = @{NSForegroundColorAttributeName: [UIColor greenColor],
NSUnderlineColorAttributeName: [UIColor lightGrayColor],
NSUnderlineStyleAttributeName: @(NSUnderlinePatternSolid)};
// assume that textView is a UITextView previously created (either by code or Interface Builder)
textView.linkTextAttributes = linkAttributes; // customizes the appearance of links
textView.attributedText = attributedString;
textView.delegate = self;
要检测这些链接点击,实现这个:
- (BOOL)textView:(UITextView *)textView shouldInteractWithURL:(NSURL *)URL inRange:(NSRange)characterRange {
if ([[URL scheme] isEqualToString:@"username"]) {
NSString *username = [URL host];
// do something with this username
// ...
return NO;
}
return YES; // let the system open this URL
}
PS:确保你的UITextView是可选的。
其他回答
UIButtonTypeCustom是一个可点击的标签,如果你没有为它设置任何图像。
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
}
从iOS 15开始,SwiftUI内置支持Markdown标记语言,因此Markdown中的文本:
Text("You can [click this link](https://www.example.com) to visit the website.")
或者作为一个使用SwiftUI的最简单的例子,你可以这样做:
HStack() {
Text("Open the")
.foregroundColor(.black)
Link(destination: URL(string: "https://www.example.com/TOS.html")!) {
Text("link")
.foregroundColor(.blue)
.underline()
}
Text("in browser")
.foregroundColor(.black)
}
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。
标签# Swift2.0
我从- excellent - @NAlexN的回答中获得灵感,我决定自己写一个UILabel的包装器。 我还尝试了TTTAttributedLabel,但我不能使它工作。
希望你能欣赏这段代码,欢迎任何建议!
import Foundation
@objc protocol TappableLabelDelegate {
optional func tappableLabel(tabbableLabel: TappableLabel, didTapUrl: NSURL, atRange: NSRange)
}
/// Represent a label with attributed text inside.
/// We can add a correspondence between a range of the attributed string an a link (URL)
/// By default, link will be open on the external browser @see 'openLinkOnExternalBrowser'
class TappableLabel: UILabel {
// MARK: - Public properties -
var links: NSMutableDictionary = [:]
var openLinkOnExternalBrowser = true
var delegate: TappableLabelDelegate?
// MARK: - Constructors -
override func awakeFromNib() {
super.awakeFromNib()
self.enableInteraction()
}
override init(frame: CGRect) {
super.init(frame: frame)
self.enableInteraction()
}
required init?(coder aDecoder: NSCoder) {
super.init(coder: aDecoder)
}
private func enableInteraction() {
self.userInteractionEnabled = true
self.addGestureRecognizer(UITapGestureRecognizer(target: self, action: Selector("didTapOnLabel:")))
}
// MARK: - Public methods -
/**
Add correspondence between a range and a link.
- parameter url: url.
- parameter range: range on which couple url.
*/
func addLink(url url: String, atRange range: NSRange) {
self.links[url] = range
}
// MARK: - Public properties -
/**
Action rised on user interaction on label.
- parameter tapGesture: gesture.
*/
func didTapOnLabel(tapGesture: UITapGestureRecognizer) {
let labelSize = self.bounds.size;
let layoutManager = NSLayoutManager()
let textContainer = NSTextContainer(size: CGSizeZero)
let textStorage = NSTextStorage(attributedString: self.attributedText!)
// configure textContainer for the label
textContainer.lineFragmentPadding = 0
textContainer.lineBreakMode = self.lineBreakMode
textContainer.maximumNumberOfLines = self.numberOfLines
textContainer.size = labelSize;
// configure layoutManager and textStorage
layoutManager.addTextContainer(textContainer)
textStorage.addLayoutManager(layoutManager)
// find the tapped character location and compare it to the specified range
let locationOfTouchInLabel = tapGesture.locationInView(self)
let textBoundingBox = layoutManager.usedRectForTextContainer(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 locationOfTouchInTextContainer = CGPointMake(locationOfTouchInLabel.x - textContainerOffset.x,
locationOfTouchInLabel.y - textContainerOffset.y)
let indexOfCharacter = layoutManager.characterIndexForPoint(locationOfTouchInTextContainer,
inTextContainer:textContainer,
fractionOfDistanceBetweenInsertionPoints: nil)
for (url, value) in self.links {
if let range = value as? NSRange {
if NSLocationInRange(indexOfCharacter, range) {
let url = NSURL(string: url as! String)!
if self.openLinkOnExternalBrowser {
UIApplication.sharedApplication().openURL(url)
}
self.delegate?.tappableLabel?(self, didTapUrl: url, atRange: range)
}
}
}
}
}
推荐文章
- 如何使用Xcode创建。ipa文件?
- 动态改变UILabel的字体大小
- 在iPhone上确定用户是否启用了推送通知
- 是否有可能禁用浮动头在UITableView与UITableViewStylePlain?
- 错误ITMS-9000:“冗余二进制文件上传。火车1.0版本已经有一个二进制版本上传。
- Swift -转换为绝对值
- 从父iOS访问容器视图控制器
- 自定义dealloc和ARC (Objective-C)
- 调整UITableView的大小以适应内容
- 在代码中为UIButton设置一个图像
- NSRange从Swift Range?
- UICollectionView中的单元格间距
- 我如何在我的iOS应用程序中每n分钟得到一个后台位置更新?
- 如何使用iOS创建GUID/UUID
- 禁用所呈现视图控制器的交互式撤销