title: Make ImageView Circular
body: <p>I have an ImageView which I am attempting to make Circular in Xamarin. This would be simple enough and I would have done it with Core Animation, but the images are being downloaded Asynchronously like this:</p>
  
  <pre><code>this.profileImage.InvokeOnMainThread (() =&gt; this.profileImage.SetImage (
      url: new NSUrl (datum.user.profile_picture)
      )
  ); 
  </code></pre>
  
  <p>How would I make these images circular?</p>