title: Why does the ActionBar not show when I extend from ListActivity instead of ActionBarActivity?
body: <p>When I change the activity to extend from <code>ListActivity</code> instead of <code>ActionBarActivity</code> the action bar is removed.</p>
  
  <p><code>public class MainActivity extends ListActivity {</code></p>
  
  <p>changed to:</p>
  
  <p><code>public class MainActivity extends ActionBarActivity {</code></p>
  
  <p><strong>Contents of activity_main.xml:</strong></p>
  
  <pre><code>&lt;RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:id="@+id/layout"&gt;
  
      &lt;ListView
          android:layout_width="wrap_content"
          android:layout_height="wrap_content"
          android:id="@android:id/list"
           /&gt;
  
      &lt;ProgressBar
          android:layout_width="wrap_content"
          android:layout_height="wrap_content"
          android:id="@+id/progressBar"
          android:layout_centerInParent="true"
          android:visibility="invisible"/&gt;
  
  &lt;/RelativeLayout&gt;
  </code></pre>