. lang。ClassCastException:片段不能转换为android.support.v4.app.Fragment。

I am trying to implement Tab Navigation, I have a Container Activity that extends Fragment Activity, and this Activity creates a TabView using an ActionBar. The app will try to create three tabs and add them to the ActionBar, and I want to change the fragment depending on the TabSelection..But occured an error I am trying to implement Tab Navigation, I have