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
我扩展了@samwize的答案来处理多行UILabel，并给出了一个使用UIButton的例子
extension UITapGestureRecognizer {
func didTapAttributedTextInButton(button: UIButton, inRange targetRange: NSRange) -> Bool {
guard let label = button.titleLabel else { return false }
return didTapAttributedTextInLabel(label, inRange: targetRange)
}
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.locationInView(label)
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),
0 );
// Adjust for multiple lines of text
let lineModifier = Int(ceil(locationOfTouchInLabel.y / label.font.lineHeight)) - 1
let rightMostFirstLinePoint = CGPointMake(labelSize.width, 0)
let charsPerLine = layoutManager.characterIndexForPoint(rightMostFirstLinePoint, inTextContainer: textContainer, fractionOfDistanceBetweenInsertionPoints: nil)
let indexOfCharacter = layoutManager.characterIndexForPoint(locationOfTouchInTextContainer, inTextContainer: textContainer, fractionOfDistanceBetweenInsertionPoints: nil)
let adjustedRange = indexOfCharacter + (lineModifier * charsPerLine)
return NSLocationInRange(adjustedRange, targetRange)
}
}
其他回答
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。
我正在扩展@NAlexN原始的详细解决方案，与@zekel优秀的UITapGestureRecognizer扩展，并在Swift中提供。
Extending UITapGestureRecognizer
extension UITapGestureRecognizer {
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 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)
}
}
使用
设置UIGestureRecognizer发送动作到tapLabel:，你可以检测目标范围是否在myLabel上被点击。
@IBAction func tapLabel(gesture: UITapGestureRecognizer) {
if gesture.didTapAttributedTextInLabel(myLabel, inRange: targetRange1) {
print("Tapped targetRange1")
} else if gesture.didTapAttributedTextInLabel(myLabel, inRange: targetRange2) {
print("Tapped targetRange2")
} else {
print("Tapped none")
}
}
重要提示:UILabel换行模式必须设置为按word/char换行。以某种方式，只有当换行模式为其他模式时，NSTextContainer才会假定文本为单行。
Drop-in解决方案作为UILabel上的一个类别(这假设你的UILabel使用一个带有NSLinkAttributeName属性的带属性字符串):
@implementation UILabel (Support)
- (BOOL)openTappedLinkAtLocation:(CGPoint)location {
CGSize labelSize = self.bounds.size;
NSTextContainer* textContainer = [[NSTextContainer alloc] initWithSize:CGSizeZero];
textContainer.lineFragmentPadding = 0.0;
textContainer.lineBreakMode = self.lineBreakMode;
textContainer.maximumNumberOfLines = self.numberOfLines;
textContainer.size = labelSize;
NSLayoutManager* layoutManager = [[NSLayoutManager alloc] init];
[layoutManager addTextContainer:textContainer];
NSTextStorage* textStorage = [[NSTextStorage alloc] initWithAttributedString:self.attributedText];
[textStorage addAttribute:NSFontAttributeName value:self.font range:NSMakeRange(0, textStorage.length)];
[textStorage addLayoutManager:layoutManager];
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(location.x - textContainerOffset.x, location.y - textContainerOffset.y);
NSInteger indexOfCharacter = [layoutManager characterIndexForPoint:locationOfTouchInTextContainer inTextContainer:textContainer fractionOfDistanceBetweenInsertionPoints:nullptr];
if (indexOfCharacter >= 0) {
NSURL* url = [textStorage attribute:NSLinkAttributeName atIndex:indexOfCharacter effectiveRange:nullptr];
if (url) {
[[UIApplication sharedApplication] openURL:url];
return YES;
}
}
return NO;
}
@end
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;
}
}
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)
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