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
有些答案并不如我所料。这是Swift解决方案,也支持textAlignment和多行。不需要子类化,只是这个UITapGestureRecognizer扩展:
import UIKit
extension UITapGestureRecognizer {
func didTapAttributedString(_ string: String, in label: UILabel) -> Bool {
guard let text = label.text else {
return false
}
let range = (text as NSString).range(of: string)
return self.didTapAttributedText(label: label, inRange: range)
}
private func didTapAttributedText(label: UILabel, inRange targetRange: NSRange) -> Bool {
guard let attributedText = label.attributedText else {
assertionFailure("attributedText must be set")
return false
}
let textContainer = createTextContainer(for: label)
let layoutManager = NSLayoutManager()
layoutManager.addTextContainer(textContainer)
let textStorage = NSTextStorage(attributedString: attributedText)
if let font = label.font {
textStorage.addAttribute(NSAttributedString.Key.font, value: font, range: NSMakeRange(0, attributedText.length))
}
textStorage.addLayoutManager(layoutManager)
let locationOfTouchInLabel = location(in: label)
let textBoundingBox = layoutManager.usedRect(for: textContainer)
let alignmentOffset = aligmentOffset(for: label)
let xOffset = ((label.bounds.size.width - textBoundingBox.size.width) * alignmentOffset) - textBoundingBox.origin.x
let yOffset = ((label.bounds.size.height - textBoundingBox.size.height) * alignmentOffset) - textBoundingBox.origin.y
let locationOfTouchInTextContainer = CGPoint(x: locationOfTouchInLabel.x - xOffset, y: locationOfTouchInLabel.y - yOffset)
let characterTapped = layoutManager.characterIndex(for: locationOfTouchInTextContainer, in: textContainer, fractionOfDistanceBetweenInsertionPoints: nil)
let lineTapped = Int(ceil(locationOfTouchInLabel.y / label.font.lineHeight)) - 1
let rightMostPointInLineTapped = CGPoint(x: label.bounds.size.width, y: label.font.lineHeight * CGFloat(lineTapped))
let charsInLineTapped = layoutManager.characterIndex(for: rightMostPointInLineTapped, in: textContainer, fractionOfDistanceBetweenInsertionPoints: nil)
return characterTapped < charsInLineTapped ? targetRange.contains(characterTapped) : false
}
private func createTextContainer(for label: UILabel) -> NSTextContainer {
let textContainer = NSTextContainer(size: label.bounds.size)
textContainer.lineFragmentPadding = 0.0
textContainer.lineBreakMode = label.lineBreakMode
textContainer.maximumNumberOfLines = label.numberOfLines
return textContainer
}
private func aligmentOffset(for label: UILabel) -> CGFloat {
switch label.textAlignment {
case .left, .natural, .justified:
return 0.0
case .center:
return 0.5
case .right:
return 1.0
@unknown default:
return 0.0
}
}
}
用法:
class ViewController: UIViewController {
@IBOutlet var label : UILabel!
let selectableString1 = "consectetur"
let selectableString2 = "cupidatat"
override func viewDidLoad() {
super.viewDidLoad()
let text = "Lorem ipsum dolor sit amet, \(selectableString1) adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat \(selectableString2) non proident, sunt in culpa qui officia deserunt mollit anim id est laborum."
label.attributedText = NSMutableAttributedString(attributedString: NSAttributedString(string: text))
let tapGesture = UITapGestureRecognizer(target: self, action: #selector(labelTapped))
label.addGestureRecognizer(tapGesture)
label.isUserInteractionEnabled = true
}
@objc func labelTapped(gesture: UITapGestureRecognizer) {
if gesture.didTapAttributedString(selectableString1, in: label) {
print("\(selectableString1) tapped")
} else if gesture.didTapAttributedString(selectableString2, in: label) {
print("\(selectableString2) tapped")
} else {
print("Text tapped")
}
}
}
其他回答
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。
我找到了另一个解决方案:
我找到了一种方法来检测你从互联网上找到的html文本链接,你把它转换成nsattributeString:
func htmlAttributedString(fontSize: CGFloat = 17.0) -> NSAttributedString? {
let fontName = UIFont.systemFont(ofSize: fontSize).fontName
let string = self.appending(String(format: "<style>body{font-family: '%@'; font-size:%fpx;}</style>", fontName, fontSize))
guard let data = string.data(using: String.Encoding.utf16, allowLossyConversion: false) else { return nil }
guard let html = try? NSMutableAttributedString (
data: data,
options: [NSAttributedString.DocumentReadingOptionKey.documentType: NSAttributedString.DocumentType.html],
documentAttributes: nil) else { return nil }
return html
}
我的方法允许您检测超链接,而无需指定它们。
first you create an extension of the tapgesturerecognizer : 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) } }
然后在你的视图控制器中,你创建了一个url和范围列表来存储属性文本包含的所有链接和范围:
var listurl : [String] = []
var listURLRange : [NSRange] = []
找到URL和URLRange,你可以使用:
fun findLinksAndRange(attributeString : NSAttributeString){
notification.enumerateAttribute(NSAttributedStringKey.link , in: NSMakeRange(0, notification.length), options: [.longestEffectiveRangeNotRequired]) { value, range, isStop in
if let value = value {
print("\(value) found at \(range.location)")
let stringValue = "\(value)"
listurl.append(stringValue)
listURLRange.append(range)
}
}
westlandNotifcationLabel.addGestureRecognizer(UITapGestureRecognizer(target : self, action: #selector(handleTapOnLabel(_:))))
}
然后你实现了手柄tap:
@objc func handleTapOnLabel(_ recognizer: UITapGestureRecognizer) {
for index in 0..<listURLRange.count{
if recognizer.didTapAttributedTextInLabel(label: westlandNotifcationLabel, inRange: listURLRange[index]) {
goToWebsite(url : listurl[index])
}
}
}
func goToWebsite(url : String){
if let websiteUrl = URL(string: url){
if #available(iOS 10, *) {
UIApplication.shared.open(websiteUrl, options: [:],
completionHandler: {
(success) in
print("Open \(websiteUrl): \(success)")
})
} else {
let success = UIApplication.shared.openURL(websiteUrl)
print("Open \(websiteUrl): \(success)")
}
}
}
开始了!
我希望这个解决方案能帮助你,就像它帮助我一样。
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)
}
(我的回答建立在@NAlexN的精彩回答之上。我不会在这里重复他对每一步的详细解释。)
我发现这是最方便和直接的添加支持可点击的UILabel文本作为类别UITapGestureRecognizer。(你不必使用UITextView的数据检测器,就像一些答案所建议的那样。)
添加以下方法到你的UITapGestureRecognizer类别:
/**
Returns YES if the tap gesture was within the specified range of the attributed text of the label.
*/
- (BOOL)didTapAttributedTextInLabel:(UILabel *)label inRange:(NSRange)targetRange {
NSParameterAssert(label != nil);
CGSize labelSize = label.bounds.size;
// create instances of NSLayoutManager, NSTextContainer and NSTextStorage
NSLayoutManager *layoutManager = [[NSLayoutManager alloc] init];
NSTextContainer *textContainer = [[NSTextContainer alloc] initWithSize:CGSizeZero];
NSTextStorage *textStorage = [[NSTextStorage alloc] initWithAttributedString:label.attributedText];
// configure layoutManager and textStorage
[layoutManager addTextContainer:textContainer];
[textStorage addLayoutManager:layoutManager];
// configure textContainer for the label
textContainer.lineFragmentPadding = 0.0;
textContainer.lineBreakMode = label.lineBreakMode;
textContainer.maximumNumberOfLines = label.numberOfLines;
textContainer.size = labelSize;
// find the tapped character location and compare it to the specified range
CGPoint locationOfTouchInLabel = [self locationInView:label];
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(locationOfTouchInLabel.x - textContainerOffset.x,
locationOfTouchInLabel.y - textContainerOffset.y);
NSInteger indexOfCharacter = [layoutManager characterIndexForPoint:locationOfTouchInTextContainer
inTextContainer:textContainer
fractionOfDistanceBetweenInsertionPoints:nil];
if (NSLocationInRange(indexOfCharacter, targetRange)) {
return YES;
} else {
return NO;
}
}
示例代码
// (in your view controller)
// create your label, gesture recognizer, attributed text, and get the range of the "link" in your label
myLabel.userInteractionEnabled = YES;
[myLabel addGestureRecognizer:
[[UITapGestureRecognizer alloc] initWithTarget:self
action:@selector(handleTapOnLabel:)]];
// create your attributed text and keep an ivar of your "link" text range
NSAttributedString *plainText;
NSAttributedString *linkText;
plainText = [[NSMutableAttributedString alloc] initWithString:@"Add label links with UITapGestureRecognizer"
attributes:nil];
linkText = [[NSMutableAttributedString alloc] initWithString:@" Learn more..."
attributes:@{
NSForegroundColorAttributeName:[UIColor blueColor]
}];
NSMutableAttributedString *attrText = [[NSMutableAttributedString alloc] init];
[attrText appendAttributedString:plainText];
[attrText appendAttributedString:linkText];
// ivar -- keep track of the target range so you can compare in the callback
targetRange = NSMakeRange(plainText.length, linkText.length);
手势回调
// handle the gesture recognizer callback and call the category method
- (void)handleTapOnLabel:(UITapGestureRecognizer *)tapGesture {
BOOL didTapLink = [tapGesture didTapAttributedTextInLabel:myLabel
inRange:targetRange];
NSLog(@"didTapLink: %d", didTapLink);
}
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