title: CGAffineTransform to View center
body: <p>I am using <code>self.logoImage.transform = CGAffineTransform(translationX: 0.0, y: 250)</code> to move my logo to the center of the screen when a button is clicked, however I would like to be sure it moves to the exact center of the screen on any device (<code>250</code> here does the trick on my iPhone 6 only).</p>
  
  <p>How can I do? I failed trying CGPoint or maybe couldn't find the correct info.</p>