如何在UITextView的特定行上检测点击？

Question

I have a UITextview i want to make few words as link so that i can detect tap on them and get a callback function. I have made link property of UITextView as checked and Implemented below delegate methods.

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

@available(iOS 10.0, *)
func textView(_ textView: UITextView, shouldInteractWith URL: URL, in characterRange: NSRange, interaction: UITextItemInteraction) -> Bool {
    print("bye")
    return true
} 

I have also made the string bold and italic by using NSMutableString

let str = NSMutableAttributedString(string: self.tvBottom.text as String, attributes: [NSFontAttributeName:UIFont.systemFont(ofSize: 17.0)])
str.addAttribute(NSLinkAttributeName, value: "http://www.google.com", range: NSRange(location: 4, length: 14))
str.addAttribute(NSForegroundColorAttributeName, value: UIColor.blue , range: NSRange(location: 4, length: 14))
let boldFontAttribute = [NSFontAttributeName: UIFont.boldSystemFont(ofSize: 17.0)]
str.addAttributes(boldFontAttribute, range: NSRange(location: 4, length: 14))
str.addAttribute(NSUnderlineStyleAttributeName , value: NSUnderlineStyle.styleSingle.rawValue, range: NSRange(location: 4, length: 14))
self.tvBottom.attributedText = str

How can I do this?

Answer 1

To detect a tap on a particular line (as your question's title suggests), then the following code would do the job:

func didTapTextView(recognizer: UITapGestureRecognizer) {
    if recognizer.state == .recognized {
        let location = recognizer.location(ofTouch: 0, in: textView)

        if location.y >= 0 && location.y <= textView.contentSize.height {
            guard let font = textView.font else {
                return
            }

            let line = Int((location.y - textView.textContainerInset.top) / font.lineHeight) + 1
            print("Line is \(line)")
        }
    }
}

The code below is used to call the method above when a tap is detected on our textView.

let tap = UITapGestureRecognizer(target: self, action: #selector(didTapTextView(recognizer:)))
tap.cancelsTouchesInView = false
textView.addGestureRecognizer(tap)

However, if you only want to detect taps on links, then you should conform to the UITextViewDelegate protocol, and implement the following method:

func textView(_ textView: UITextView, shouldInteractWith URL: URL, in characterRange: NSRange, interaction: UITextItemInteraction) -> Bool {
    return true
}

Of course, you need to add the delegate to your textView (eg in viewDidLoad() )

textView.delegate = self

PS your UITextView should not be editable.