title: How to change font of buttons in UIAlertController
body: <p>I need to change font of buttons in UIAlertController, I've used the code below, but I doesn't work properly, because when the user touches the buttons of UIAlertController, the font will be change to it's default.</p>
  
  <pre><code>extension UIAlertController {
  
      private func changeFont(view:UIView,font:UIFont) {
          for item in view.subviews {
              if let col = item as? UICollectionView {
                  for  row in col.subviews{
                      changeFont(view: row, font: font)
                  }
              }
              if let label  = item as? UILabel {
                  label.font = font
              } else {
                  changeFont(view: item, font: font)
              }
  
           }
       }
  
       //To set font for any UILabels in action sheet
       open override func viewWillLayoutSubviews() {
           super.viewWillLayoutSubviews()
           let font = MyCustomFont
           changeFont(view: self.view, font: font! )
       }
  }
  </code></pre>
  
  <p>and here is the usage of this extension: </p>
  
  <pre><code>    let optionMenu = UIAlertController(title: nil, message: nil, preferredStyle: .actionSheet)
  
      let action = UIAlertAction(title: STRING_OF_ACTION, style: .default) { _ in
          //some action code
      }
      optionMenu.addAction(action)
  
      //in UIViewController 
      self.present(optionMenu, animated: true, completion: nil)
  </code></pre>