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
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。
其他回答
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。
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。
以下是基于@Luca Davanzo的回答,重写touchesBegan事件而不是轻触手势:
import UIKit
public protocol TapableLabelDelegate: NSObjectProtocol {
func tapableLabel(_ label: TapableLabel, didTapUrl url: String, atRange range: NSRange)
}
public class TapableLabel: UILabel {
private var links: [String: NSRange] = [:]
private(set) var layoutManager = NSLayoutManager()
private(set) var textContainer = NSTextContainer(size: CGSize.zero)
private(set) var textStorage = NSTextStorage() {
didSet {
textStorage.addLayoutManager(layoutManager)
}
}
public weak var delegate: TapableLabelDelegate?
public override var attributedText: NSAttributedString? {
didSet {
if let attributedText = attributedText {
textStorage = NSTextStorage(attributedString: attributedText)
} else {
textStorage = NSTextStorage()
links = [:]
}
}
}
public override var lineBreakMode: NSLineBreakMode {
didSet {
textContainer.lineBreakMode = lineBreakMode
}
}
public override var numberOfLines: Int {
didSet {
textContainer.maximumNumberOfLines = numberOfLines
}
}
public override init(frame: CGRect) {
super.init(frame: frame)
setup()
}
public required init?(coder aDecoder: NSCoder) {
super.init(coder: aDecoder)
setup()
}
public override func layoutSubviews() {
super.layoutSubviews()
textContainer.size = bounds.size
}
/// addLinks
///
/// - Parameters:
/// - text: text of link
/// - url: link url string
public func addLink(_ text: String, withURL url: String) {
guard let theText = attributedText?.string as? NSString else {
return
}
let range = theText.range(of: text)
guard range.location != NSNotFound else {
return
}
links[url] = range
}
private func setup() {
isUserInteractionEnabled = true
layoutManager.addTextContainer(textContainer)
textContainer.lineFragmentPadding = 0
textContainer.lineBreakMode = lineBreakMode
textContainer.maximumNumberOfLines = numberOfLines
}
public override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) {
guard let locationOfTouch = touches.first?.location(in: self) else {
return
}
textContainer.size = bounds.size
let indexOfCharacter = layoutManager.glyphIndex(for: locationOfTouch, in: textContainer)
for (urlString, range) in links {
if NSLocationInRange(indexOfCharacter, range), let url = URL(string: urlString) {
delegate?.tapableLabel(self, didTapUrl: urlString, atRange: range)
}
}
}}
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()
}
}
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
}
}
}
}
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