UISearchBar access to clear text button for UIAccessibility

For a personal application conform to UIAccessibility and VoiceOver I need to change the UIAccessibilty label of the clear text button (gray cross) in a UISearchBar.

I don't now how to access to this element.

I try something like

class ViewController: UIViewController, UISearchBarDelegate
{
  @IBOutlet weak var searchBar: UISearchBar!

  weak var btnCancel: UIButton?

  override func viewDidLoad()
  {
    super.viewDidLoad()

    for subView in searchBar.subviews
    {
      for subSubView in subView.subviews
      {
        if subSubView.isKindOfClass(UIButton)
        {
          btnCancel = subSubView as? UIButton

          btnCancel?.isAccessibilityElement = true

          btnCancel?.accessibilityLabel =  NSLocalizedString("Clear Text", comment: "")
        }
      }
    }
  }
}

I try it on viewDidLoad ; searchBar textDidChange ; searchBarTextDidBeginEditing ;

I never found any button

Your help is welcome

Thanks to Joanna Carter from french website Cocoacafe.fr

Solution :

@IBOutlet weak var searchBar: UISearchBar!

  override func viewDidLoad()
  {
    super.viewDidLoad()

    for subView in searchBar.subviews
    {
      for sView in subView.subviews
      {
        if let textField = sView as? UITextField,
           let clearButton = textField.valueForKey("clearButton") as? UIButton
        {
          clearButton.isAccessibilityElement = true

          clearButton.accessibilityLabel =  NSLocalizedString("Clear Text", comment: "")
        }
      }
    }
  }