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
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;
}
}
其他回答
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
}
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()
}
}
斯威夫特5.2
我在之前的回答中发现了多行文本标签的几个问题,所以我给出了我最终的工作解决方案。
它解决了多行和文本对齐的问题。
func didTapAttributedTextInLabel(label: UILabel, inRange targetRange: NSRange) -> Bool {
// Create instances of NSLayoutManager, NSTextContainer and NSTextStorage
let layoutManager = NSLayoutManager()
let textContainer = NSTextContainer(size: CGSize.zero)
let textStorage = NSTextStorage(attributedString: label.attributedText!)
// Configure layoutManager and textStorage
layoutManager.addTextContainer(textContainer)
textStorage.addLayoutManager(layoutManager)
// Configure textContainer
textContainer.lineFragmentPadding = 0.0
textContainer.lineBreakMode = label.lineBreakMode
textContainer.maximumNumberOfLines = label.numberOfLines
let labelSize = label.bounds.size
textContainer.size = labelSize
// Find the tapped character location and compare it to the specified range
let locationOfTouchInLabel = self.location(in: label)
let textBoundingBox = layoutManager.usedRect(for: textContainer)
let textAligmentOffset = aligmentOffset(for: label)
let textContainerOffset = CGPoint(x: (labelSize.width - textBoundingBox.size.width) * textAligmentOffset - textBoundingBox.origin.x,
y: (labelSize.height - textBoundingBox.size.height) * textAligmentOffset - textBoundingBox.origin.y)
let locationOfTouchInTextContainer = CGPoint(x: (locationOfTouchInLabel.x - textContainerOffset.x),
y: 0 )
// Adjust for multiple lines of text
let lineModifier = Int(floor(locationOfTouchInLabel.y / label.font.lineHeight)) - 1
let rightMostFirstLinePoint = CGPoint(x: labelSize.width,
y: 0)
let charsPerLine = layoutManager.characterIndex(for: rightMostFirstLinePoint, in: textContainer, fractionOfDistanceBetweenInsertionPoints: nil)
let indexOfCharacter = layoutManager.characterIndex(for: locationOfTouchInTextContainer, in: textContainer, fractionOfDistanceBetweenInsertionPoints: nil)
let adjustedRange = indexOfCharacter + (lineModifier * charsPerLine)
return NSLocationInRange(adjustedRange, targetRange)
}
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
}
}
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)
这是沙玛林。基于Kedar的答案的iOS c#实现。
MyClickableTextViewWithCustomUrlScheme实现与ShouldInteractWithUrl覆盖:
// Inspired from https://stackoverflow.com/a/44112932/15186
internal class MyClickableTextViewWithCustomUrlScheme : UITextView, IUITextViewDelegate
{
public MyClickableTextViewWithCustomUrlScheme()
{
Initialize();
}
public MyClickableTextViewWithCustomUrlScheme(Foundation.NSCoder coder) : base(coder)
{
Initialize();
}
public MyClickableTextViewWithCustomUrlScheme(Foundation.NSObjectFlag t) : base(t)
{
Initialize();
}
public MyClickableTextViewWithCustomUrlScheme(IntPtr handle) : base(handle)
{
Initialize();
}
public MyClickableTextViewWithCustomUrlScheme(CoreGraphics.CGRect frame) : base(frame)
{
Initialize();
}
public MyClickableTextViewWithCustomUrlScheme(CoreGraphics.CGRect frame, NSTextContainer textContainer) : base(frame, textContainer)
{
Initialize();
}
void Initialize()
{
Delegate = this;
}
[Export("textView:shouldInteractWithURL:inRange:")]
public new bool ShouldInteractWithUrl(UITextView textView, NSUrl URL, NSRange characterRange)
{
if (URL.Scheme.CompareTo(@"username") == 0)
{
// Launch the Activity
return false;
}
// The system will handle the URL
return base.ShouldInteractWithUrl(textView, URL, characterRange);
}
}
在c#中转换的objective-C代码变成:
MyClickableTextViewWithCustomUrlScheme uiHabitTile = new MyClickableTextViewWithCustomUrlScheme();
uiHabitTile.Selectable = true;
uiHabitTile.ScrollEnabled = false;
uiHabitTile.Editable = false;
// https://stackoverflow.com/a/34014655/15186
string wholeTitle = @"This is an example by marcelofabri";
NSMutableAttributedString attributedString = new NSMutableAttributedString(wholeTitle);
attributedString.AddAttribute(UIStringAttributeKey.Link,
new NSString("username://marcelofabri"),
attributedString.Value.RangeOfString(@"marcelofabri")
);
NSMutableDictionary<NSString, NSObject> linkAttributes = new NSMutableDictionary<NSString, NSObject>();
linkAttributes[UIStringAttributeKey.ForegroundColor] = UIColor.Green;
linkAttributes[UIStringAttributeKey.UnderlineColor] = UIColor.LightGray;
linkAttributes[UIStringAttributeKey.UnderlineStyle] = new NSNumber((short)NSUnderlineStyle.PatternSolid);
uiHabitTile.AttributedText = attributedString;
确保将Editable = false和Selectable = true设置为能够单击链接。
同样,ScrollEnabled = true允许textview正确地调整其高度大小。
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