title: iOS Search Controller - show search bar at the start
body: <p>I want to show the Search engine when viewLoad the controller.
  I do not mean:</p>
  
  <pre><code>navigationItem.hidesSearchBarWhenScrolling = false
  </code></pre>
  
  <p>I want to hide the search engine while scrolling.
  I only want to show it once at the start,
  How can I do this?</p>
  
  <p><a href="https://i.stack.imgur.com/hWr5v.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/hWr5v.jpg" alt="enter image description here"></a></p>