title: Swift 3: how can I detect the touch event on UIScrollView?
body: <p>I used the below function to detect the touch event on scroll view.</p>
  
  <pre><code>override func touchesBegan(_ touches: Set&lt;UITouch&gt;, with event: UIEvent?) 
  </code></pre>
  
  <p>But this can't detect any touch event.
  How can I detect touch event on scroll view?</p>