title: Xamarin Activity OnCreate ActionBar is null
body: <p>I just upgraded Xamarin to their next "stable" version. I seem to be having issues with my class that inherits Activity. The ActionBar seems to be null for some reason when it wasn't before. I'm quite puzzled as to why this is happening now.</p>
  
  <pre><code>public class NavigationDrawerActivity : Activity
  {
      //...
  
      protected override void OnCreate (Bundle savedInstanceState)
      {
  
          base.OnCreate (savedInstanceState);
  
          //...
          // NullPointerException, this.ActionBar is null.
          this.ActionBar.SetDisplayHomeAsUpEnabled (true);
          this.ActionBar.SetHomeButtonEnabled (true);
  
          //...       
      }
      //...
  }
  </code></pre>
  
  <p>This code is based off of this: <a href="http://developer.xamarin.com/samples/NavigationDrawer/" rel="nofollow">http://developer.xamarin.com/samples/NavigationDrawer/</a></p>
  
  <p>Does anyone have any ideas as to what might be causing this?</p>