title: During Phone call using custom UIview
body: <p>I can start a phone call using this code</p>
  
  <pre><code>var url = NSUrl.FromString("tel:+xxxxx"); 
  UIApplication.SharedApplication.OpenUrl(url);
  </code></pre>
  
  <p>it opens iphones phone call ui. can i use a custome ui during this call. for example i want to show an image.</p>