title: UItextView delegate swift - textViewDidBeginEditing not called
body: <p>I've seen the other topics dealing with <code>UITextView</code> delegate, but can't seem to find where my issue come from.
  Here is my code, but when I modify my <code>UITextView</code>, nothing happens and <code>textViewDidBeginEditing</code> is not called. </p>
  
  <pre><code>import UIKit
  var textView1 = UITextView()
  
  class ViewController: UIViewController, UITextViewDelegate {
      override func viewDidLoad() {
          super.viewDidLoad()
  
          textView1.delegate = self
          textView1 = UITextView(frame: CGRect(x:24,y: 100,width: 340,height: 290))
          textView1.textColor = UIColor.black
          textView1.backgroundColor = UIColor(red: 0.00, green: 0.00, blue: 0.00, alpha: 0.00)
          textView1.text = "textView 1"
          view.addSubview(textView1)
      }
  
      func textViewDidBeginEditing(_ textView: UITextView) {
          print("print1")
      }
  
      func textViewDidEndEditing(_ textView: UITextView) { 
          print("print2")
      }
  }
  </code></pre>
  
  <p>I've tried with <code>UITextField</code>, but nothing changed, delegate functions still not called.</p>