title: UIScrollView and auto layout not working
body: <p>I'm trying to make a view scrollable in my app.</p>
  
  <p>O follow exactly the steps in tutorial <a href="https://www.youtube.com/watch?v=UnQsFlMGDsI" rel="nofollow noreferrer">https://www.youtube.com/watch?v=UnQsFlMGDsI</a> .</p>
  
  <p>The main steps I did were:</p>
  
  <ul>
  <li>Add a UIscrollView</li>
  <li>Add a view into UIscrollView (Content View)</li>
  <li>Create the margin constraints with value 0 (top, left, right and botton) for UIScrollView</li>
  <li>Create the margin constraints with value 0 (top, left, right and botton) for Content view</li>
  <li>Create 2 constraints of "equal width" and "equal height" between ContentView and main view</li>
  <li>... (Add some text fields)</li>
  </ul>
  
  <p>When I run the app, the scrollView doesn't work</p>
  
  <p><a href="https://i.stack.imgur.com/7iL7x.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/7iL7x.png" alt="enter image description here"></a></p>
  
  <p>I really can't make it work. I tried many ways to apply a UIScrollView and didn't get it.</p>