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
最简单可靠的方法是使用Kedar Paranjape推荐的UITextView。基于Karl Nosworthy的回答，我最终想出了一个简单的UITextView子类:
class LinkTextView: UITextView, UITextViewDelegate {
typealias Links = [String: String]
typealias OnLinkTap = (URL) -> Bool
var onLinkTap: OnLinkTap?
override init(frame: CGRect, textContainer: NSTextContainer?) {
super.init(frame: frame, textContainer: textContainer)
isEditable = false
isSelectable = true
isScrollEnabled = false //to have own size and behave like a label
delegate = self
}
required init?(coder: NSCoder) {
super.init(coder: coder)
}
func addLinks(_ links: Links) {
guard attributedText.length > 0 else {
return
}
let mText = NSMutableAttributedString(attributedString: attributedText)
for (linkText, urlString) in links {
if linkText.count > 0 {
let linkRange = mText.mutableString.range(of: linkText)
mText.addAttribute(.link, value: urlString, range: linkRange)
}
}
attributedText = mText
}
func textView(_ textView: UITextView, shouldInteractWith URL: URL, in characterRange: NSRange) -> Bool {
return onLinkTap?(URL) ?? true
}
// to disable text selection
func textViewDidChangeSelection(_ textView: UITextView) {
textView.selectedTextRange = nil
}
}
用法非常简单:
let linkTextView = LinkTextView()
let tu = "Terms of Use"
let pp = "Privacy Policy"
linkTextView.text = "Please read the Some Company \(tu) and \(pp)"
linkTextView.addLinks([
tu: "https://some.com/tu",
pp: "https://some.com/pp"
])
linkTextView.onLinkTap = { url in
print("url: \(url)")
return true
}
请注意，isScrollEnabled默认为false，因为在大多数情况下，我们需要有自己大小且没有滚动的类似标签的小视图。如果你想要一个可滚动的文本视图，就把它设为true。
还要注意，UITextView不像UILabel有默认的文本填充。要删除它，使布局与UILabel相同，只需添加:linkTextView。textContainerInset = . 0
实现onLinkTap闭包是不必要的，没有它url是由UIApplication自动打开的。
由于文本选择在大多数情况下是不可取的，但它不能关闭，它在委托方法中被解散(感谢Carson Vo)
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。
对于完全自定义的链接，你需要使用UIWebView -你可以拦截调用，这样当链接被按下时，你可以转到应用程序的其他部分。
(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);
}
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。
以下是NAlexN的回答。
class TapabbleLabel: UILabel {
let layoutManager = NSLayoutManager()
let textContainer = NSTextContainer(size: CGSize.zero)
var textStorage = NSTextStorage() {
didSet {
textStorage.addLayoutManager(layoutManager)
}
}
var onCharacterTapped: ((label: UILabel, characterIndex: Int) -> Void)?
let tapGesture = UITapGestureRecognizer()
override var attributedText: NSAttributedString? {
didSet {
if let attributedText = attributedText {
textStorage = NSTextStorage(attributedString: attributedText)
} else {
textStorage = NSTextStorage()
}
}
}
override var lineBreakMode: NSLineBreakMode {
didSet {
textContainer.lineBreakMode = lineBreakMode
}
}
override var numberOfLines: Int {
didSet {
textContainer.maximumNumberOfLines = numberOfLines
}
}
/**
Creates a new view with the passed coder.
:param: aDecoder The a decoder
:returns: the created new view.
*/
required init?(coder aDecoder: NSCoder) {
super.init(coder: aDecoder)
setUp()
}
/**
Creates a new view with the passed frame.
:param: frame The frame
:returns: the created new view.
*/
override init(frame: CGRect) {
super.init(frame: frame)
setUp()
}
/**
Sets up the view.
*/
func setUp() {
userInteractionEnabled = true
layoutManager.addTextContainer(textContainer)
textContainer.lineFragmentPadding = 0
textContainer.lineBreakMode = lineBreakMode
textContainer.maximumNumberOfLines = numberOfLines
tapGesture.addTarget(self, action: #selector(TapabbleLabel.labelTapped(_:)))
addGestureRecognizer(tapGesture)
}
override func layoutSubviews() {
super.layoutSubviews()
textContainer.size = bounds.size
}
func labelTapped(gesture: UITapGestureRecognizer) {
guard gesture.state == .Ended else {
return
}
let locationOfTouch = gesture.locationInView(gesture.view)
let textBoundingBox = layoutManager.usedRectForTextContainer(textContainer)
let textContainerOffset = CGPoint(x: (bounds.width - textBoundingBox.width) / 2 - textBoundingBox.minX,
y: (bounds.height - textBoundingBox.height) / 2 - textBoundingBox.minY)
let locationOfTouchInTextContainer = CGPoint(x: locationOfTouch.x - textContainerOffset.x,
y: locationOfTouch.y - textContainerOffset.y)
let indexOfCharacter = layoutManager.characterIndexForPoint(locationOfTouchInTextContainer,
inTextContainer: textContainer,
fractionOfDistanceBetweenInsertionPoints: nil)
onCharacterTapped?(label: self, characterIndex: indexOfCharacter)
}
}
然后你可以在你的viewDidLoad方法中创建一个类的实例，就像这样:
let label = TapabbleLabel()
label.translatesAutoresizingMaskIntoConstraints = false
view.addSubview(label)
view.addConstraints(NSLayoutConstraint.constraintsWithVisualFormat("V:|-[view]-|",
options: [], metrics: nil, views: ["view" : label]))
view.addConstraints(NSLayoutConstraint.constraintsWithVisualFormat("H:|-[view]-|",
options: [], metrics: nil, views: ["view" : label]))
let attributedString = NSMutableAttributedString(string: "String with a link", attributes: nil)
let linkRange = NSMakeRange(14, 4); // for the word "link" in the string above
let linkAttributes: [String : AnyObject] = [
NSForegroundColorAttributeName : UIColor.blueColor(), NSUnderlineStyleAttributeName : NSUnderlineStyle.StyleSingle.rawValue,
NSLinkAttributeName: "http://www.apple.com"]
attributedString.setAttributes(linkAttributes, range:linkRange)
label.attributedText = attributedString
label.onCharacterTapped = { label, characterIndex in
if let attribute = label.attributedText?.attribute(NSLinkAttributeName, atIndex: characterIndex, effectiveRange: nil) as? String,
let url = NSURL(string: attribute) {
UIApplication.sharedApplication().openURL(url)
}
}
最好有一个自定义属性，以便在点击字符时使用。它是NSLinkAttributeName，但可以是任何东西你可以使用那个值去做其他的事情除了打开一个url，你可以做任何自定义动作。
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