title: TextField in Xamarin IOS not allowing input
body: <p>I have an ios App created in Xamarin with Visual Studio on the Mac. I've modified SceneDelegate to load a UITabController that is <em>not</em> created on the Storyboard. I've done this to allow changing the number of tabs presented in some cases. </p>
  
  <p>The UITabController is adding a View that is defined on the Storyboard. This view contains a TextField, this textfield does not allow text entry. When you tap it a keyboard does not appear.</p>
  
  <p>Yes User Interaction Enabled is checked.</p>
  
  <p>How can I fix this?
  Thanks, Gerry</p>