How to make UITextView detect hashtags?

Question

I know that the UITextView default can detect URL, but how can i make it detect hashtags(#)?

It doesn\'t needs to detect hashtags while typing, but then

Answer 1

For Swift 3 +

 extension UITextView {
        
        func convertHashtags(text:String) -> NSAttributedString {
            
            let attr = [
                NSFontAttributeName : UIFont.systemFont(ofSize: 17.0),
                NSForegroundColorAttributeName : clr_golden,    
                NSLinkAttributeName : "https://Laitkor.com"
             ] as [String : Any]

        
        let attrString = NSMutableAttributedString(string: text)
        attrString.beginEditing()
        // match all hashtags
        do {
            // Find all the hashtags in our string
            let regex = try NSRegularExpression(pattern: "(?:\\s|^)(#(?:[a-zA-Z].*?|\\d+[a-zA-Z]+.*?))\\b", options: NSRegularExpression.Options.anchorsMatchLines)
            let results = regex.matches(in: text,
                                                options: NSRegularExpression.MatchingOptions.withoutAnchoringBounds, range: NSMakeRange(0, text.characters.count))
            let array = results.map { (text as NSString).substring(with: $0.range) }
            for hashtag in array {
                // get range of the hashtag in the main string
                let range = (attrString.string as NSString).range(of: hashtag)
                // add a colour to the hashtag
                //attrString.addAttribute(NSForegroundColorAttributeName, value: clr_golden , range: range)
                attrString.addAttributes(attr, range: range)
            }
            attrString.endEditing()
        }
        catch {
            attrString.endEditing()
        }
        return attrString
    }
}

Add UITextViewDelegate in your class and Use like this

 self.tv_yourTextView.delegate = self
 self.tv_yourTextView.attributedText = tv_yourTextView.convertHashtags(text: "This is an #museer test")

delegate funtion

func textView(_ textView: UITextView, shouldInteractWith URL: URL, in characterRange: NSRange) -> Bool {
    print("hastag Selected!")
    return true
}

-> Modified @Wez Answer