根据行数动态更改文本视图的高度

Question

I am dynamically changing the height of my text view based on the number of lines in my text view. I'd like the text view to start increasing in height after the 6th line. My current implementation is causing the text view to constantly increase in height because the line count is always greater than the previous count. I'd also like the text view to shrink as you remove lines:

func textViewDidChange(_ textView: UITextView) {

   let lineCount = numberOfLines(textView: textView)

      if lineCount > previousLineCount {
            previousLineCount = lineCount - 1
      }

      print("previous number of lines: \(previousLineCount) current number of lines: \(lineCount)" )

      if lineCount > 6 && lineCount > previousLineCount {
           self.layoutConstraint.constant += 4
      }
}

Any ideas?

Answer 1

Given that you add leading , trailing , top and link the height constraint you can do

func textViewDidChange(_ textView: UITextView) { 
   self.heightConstraint.constant = textView.contentSize.height
   self.view.layoutIfNeeded()
}

Answer 2

Why not:

textView.sizeToFit()

And don't forget to disable scrolling either in storyboard or:

textView.scrollEnabled = false