title: Adding actionbar to listactivity
body: <p>Hello so I created a list and I want to add action bar. I am quite new to android so I would like to know how to add action bar while using ListActivity. Any help will be appreciated. Thanks
  My code: </p>
  
  <pre><code>     public class MainActivity extends ListActivity {
  
       ArrayList&lt;Item&gt; items = new ArrayList&lt;Item&gt;();
  
      @Override
      public void onCreate(Bundle savedInstanceState) {
          super.onCreate(savedInstanceState);
  
  
          items.add(new SectionItem("2x2 Matrices"));
          items.add(new EntryItem("Adding 2 Matrices"));
          items.add(new EntryItem("Subtracting 2 Matrices"));
          items.add(new EntryItem("Multiplying 2 Matrices"));
          items.add(new EntryItem("Multiplying by a constant"));
          items.add(new EntryItem("Dividing 2 Matrices"));
          items.add(new EntryItem("Negative of a Matrix"));
          items.add(new EntryItem("Inverse of a Matrix"));
          items.add(new EntryItem("Determinant of a Matrix"));
  
          /*Section2*/
          items.add(new SectionItem("3x3 Matrices"));
          items.add(new EntryItem("Item 4"));
          items.add(new EntryItem("Item 5"));
          items.add(new EntryItem("Item 6"));
          items.add(new EntryItem("Item 7"));
          /*Section3*/
          items.add(new SectionItem("Category 3"));
          items.add(new EntryItem("Item 8"));
          items.add(new EntryItem("Item 9"));
          items.add(new EntryItem("Item 10"));
          items.add(new EntryItem("Item 11"));
          items.add(new EntryItem("Item 12"));
  
          EntryAdapter adapter = new EntryAdapter(this, items);
  
          setListAdapter(adapter);
      }
  
  }
  </code></pre>