在iOS中像Twitter应用程序中检测哈希标签＃，提及标签@
我需要检测＃描述UILabel给出的[UIColor BlueColor]; ，并将文本颜色更改为[UIColor BlueColor]; 在那里我无法改变UILabel到蓝色的特定文字颜色。 现在我在自定义的UITableViewCell使用这个UILabel 。 有什么办法来解决这个问题来区分＃ 标签和普通文本的文字颜色？ 有人可以帮我解决这个问题吗？
-(NSMutableAttributedString*)decorateTags:(NSString *)stringWithTags{ NSError *error = nil; //For "Vijay #Apple Dev" NSRegularExpression *regex = [NSRegularExpression regularExpressionWithPattern:@"#(\\w+)" options:0 error:&error]; //For "Vijay @Apple Dev" //NSRegularExpression *regex = [NSRegularExpression regularExpressionWithPattern:@"@(\\w+)" options:0 error:&error]; NSArray *matches = [regex matchesInString:stringWithTags options:0 range:NSMakeRange(0, stringWithTags.length)]; NSMutableAttributedString *attString=[[NSMutableAttributedString alloc] initWithString:stringWithTags]; NSInteger stringLength=[stringWithTags length]; for (NSTextCheckingResult *match in matches) { NSRange wordRange = [match rangeAtIndex:1]; NSString* word = [stringWithTags substringWithRange:wordRange]; //Set Font UIFont *font=[UIFont fontWithName:@"Helvetica-Bold" size:15.0f]; [attString addAttribute:NSFontAttributeName value:font range:NSMakeRange(0, stringLength)]; //Set Background Color UIColor *backgroundColor=[UIColor orangeColor]; [attString addAttribute:NSBackgroundColorAttributeName value:backgroundColor range:wordRange]; //Set Foreground Color UIColor *foregroundColor=[UIColor blueColor]; [attString addAttribute:NSForegroundColorAttributeName value:foregroundColor range:wordRange]; NSLog(@"Found tag %@", word); } // Set up your text field or label to show up the result // yourTextField.attributedText = attString; // // yourLabel.attributedText = attString; return attString; }
新增function：在iOS 9中使用此链接https://github.com/hsusmita/ResponsiveLabel
这是一个Swift解决scheme。 它使用UITextView ，它支持属性文本，多行，并支持内置的委托来将tap事件映射到选定的单词（用户在看到蓝色文本时可能期望的）。
而不是将字符的范围更改为.blueColor() ，它添加了一个链接属性，它会自动将可点击的文本设置为您的全局色调。
它还包含一些基本的支持，用于处理数字#1和特殊字符@abc.go Twitter hashtag规则。
工作示例项目：
博客文章更通用的解释：
http://www.thorntech.com/2015/06/detecting-hashtags-mentions-and-urls-with-swift/
extension UITextView { func chopOffNonAlphaNumericCharacters(text:String) -> String { var nonAlphaNumericCharacters = NSCharacterSet.alphanumericCharacterSet().invertedSet let characterArray = text.componentsSeparatedByCharactersInSet(nonAlphaNumericCharacters) return characterArray[0] } /// Call this manually if you want to hash tagify your string. func resolveHashTags(){ let schemeMap = [ "#":"hash", "@":"mention" ] // Turn string in to NSString. // NSString gives us some helpful API methods let nsText:NSString = self.text // Separate the string into individual words. // Whitespace is used as the word boundary. // You might see word boundaries at special characters, like before a period. // But we need to be careful to retain the # or @ characters. let words:[NSString] = nsText.componentsSeparatedByCharactersInSet(NSCharacterSet.whitespaceAndNewlineCharacterSet()) as! [NSString] // Attributed text overrides anything set in the Storyboard. // So remember to set your font, color, and size here. var attrs = [ // NSFontAttributeName : UIFont(name: "Georgia", size: 20.0)!, // NSForegroundColorAttributeName : UIColor.greenColor(), NSFontAttributeName : UIFont.systemFontOfSize(17.0) ] // Use an Attributed String to hold the text and fonts from above. // We'll also append to this object some hashtag URLs for specific word ranges. var attrString = NSMutableAttributedString(string: nsText as String, attributes:attrs) // Iterate over each word. // So far each word will look like: // - I // - visited // - #123abc.go! // The last word is a hashtag of #123abc // Use the following hashtag rules: // - Include the hashtag # in the URL // - Only include alphanumeric characters. Special chars and anything after are chopped off. // - Hashtags can start with numbers. But the whole thing can't be a number (#123abc is ok, #123 is not) for word in words { var scheme:String? = nil if word.hasPrefix("#") { scheme = schemeMap["#"] } else if word.hasPrefix("@") { scheme = schemeMap["@"] } // found a word that is prepended by a hashtag if let scheme = scheme { // convert the word from NSString to String // this allows us to call "dropFirst" to remove the hashtag var stringifiedWord:String = word as String // example: #123abc.go! // drop the hashtag // example becomes: 123abc.go! stringifiedWord = dropFirst(stringifiedWord) // Chop off special characters and anything after them. // example becomes: 123abc stringifiedWord = chopOffNonAlphaNumericCharacters(stringifiedWord) if let stringIsNumeric = stringifiedWord.toInt() { // don't convert to hashtag if the entire string is numeric. // example: 123abc is a hashtag // example: 123 is not } else if stringifiedWord.isEmpty { // do nothing. // the word was just the hashtag by itself. } else { // set a link for when the user clicks on this word. var matchRange:NSRange = nsText.rangeOfString(stringifiedWord as String) // Remember, we chopped off the hash tag, so: // 1.) shift this left by one character. example becomes: #123ab matchRange.location-- // 2.) and lengthen the range by one character too. example becomes: #123abc matchRange.length++ // URL syntax is http://123abc // Replace custom scheme with something like hash://123abc // URLs actually don't need the forward slashes, so it becomes hash:123abc // Custom scheme for @mentions looks like mention:123abc // As with any URL, the string will have a blue color and is clickable attrString.addAttribute(NSLinkAttributeName, value: "\(scheme):\(stringifiedWord)", range: matchRange) } } } // Use textView.attributedText instead of textView.text self.attributedText = attrString } }
用法：
textView.resolveHashTags()
处理点击事件：
func showHashTagAlert(tagType:String, payload:String){ let alertView = UIAlertView() alertView.title = "\(tagType) tag detected" // get a handle on the payload alertView.message = "\(payload)" alertView.addButtonWithTitle("Ok") alertView.show() } extension ViewController : UITextViewDelegate { func textView(textView: UITextView, shouldInteractWithURL URL: NSURL, inRange characterRange: NSRange) -> Bool { // check for our fake URL scheme hash:helloWorld if let scheme = URL.scheme { switch scheme { case "hash" : showHashTagAlert("hash", payload: URL.resourceSpecifier!) case "mention" : showHashTagAlert("mention", payload: URL.resourceSpecifier!) default: println("just a regular url") } } return true } }
你可以使用https://github.com/Krelborn/KILabel这个库。 它还检测用户在标签上的点击如下所示：
label.hashtagLinkTapHandler = ^(KILabel *label, NSString *string, NSRange range) { NSLog(@"Hashtag tapped %@", string); };