title: Need help in developing iOS/Swift
body: <p>I am newbie to iOS/Swift.
  I am developing app using Swift4 on XCode12.
  But I have a problem with presenting UIViewController.</p>
  <p>Below is my code:</p>
  <ul>
  <li><p>presenting UIViewController</p>
  <pre><code>let scanner = NewController({ ... })
  scanner.delegate = self
  self.present(scanner, animated: true, completion: nil)
  </code></pre>
  </li>
  <li><p>NewController</p>
  <pre><code>public class NewController: UIViewController, AVCaptureMetadataOutputObjectsDelegate {
    ...
  }
  </code></pre>
  </li>
  </ul>
  <p>But it shows like this image.
  <a href="https://i.stack.imgur.com/NuFX0.png" rel="nofollow noreferrer">Image before/after presenting</a></p>
  <p>As you can see in the image, it shows black margin after presenting NewController.</p>
  <p>Anybody can help me?</p>
  <p>I tested on simulator iPhone 8 (iOS 14.2).</p>