title: Xcode - using constraints
body: <p>I'm trying to expand an UIView into all available space on its parent, setup such constraints</p>
  
  <p><img src="https://i.stack.imgur.com/mGcie.png" alt="enter image description here"></p>
  
  <p>when I run the project in simulator it display ok in portrait mode it display ok, but when turning into landscape I do see a small white strip at the top</p>
  
  <p><img src="https://i.stack.imgur.com/rwRXu.png" alt="enter image description here"></p>
  
  <p>What is wrong? Any other constraints are needed?</p>
  
  <p>Thx</p>