Create ActionBar in Tab navigation mode

New a Android project target Android 3.2, API Level 13.

Create three Fragments, each one corresponding to one tab.

MyFragmentA.java

package com.exercise.AndroidNavigationTabs;

import android.app.Fragment;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;

public class MyFragmentA extends Fragment {

 @Override
 public View onCreateView(LayoutInflater inflater, ViewGroup container,
   Bundle savedInstanceState) {
  View myFragmentView = inflater.inflate(R.layout.fragment_a, container, false);
  return myFragmentView;
 }

}

/res/layout/fragment_a.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
   android:layout_width="fill_parent"
   android:layout_height="fill_parent"
   android:orientation="vertical" >
   <TextView
       android:layout_width="match_parent"
       android:layout_height="wrap_content"
       android:text="It's Fragment A" />
   <ImageView
       android:layout_width="match_parent"
       android:layout_height="match_parent"
       android:src="@drawable/ic_launcher"/>
</LinearLayout>

MyFragmentB.java

package com.exercise.AndroidNavigationTabs;

import android.app.Fragment;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;

public class MyFragmentB extends Fragment {

 @Override
 public View onCreateView(LayoutInflater inflater, ViewGroup container,
   Bundle savedInstanceState) {
  View myFragmentView = inflater.inflate(R.layout.fragment_b, container, false);
  return myFragmentView;
 }

}

/res/layout/fragment_b.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
   android:layout_width="fill_parent"
   android:layout_height="fill_parent"
   android:orientation="vertical" >
   <TextView
       android:layout_width="match_parent"
       android:layout_height="wrap_content"
       android:text="It's Fragment B" />
   <ImageView
       android:layout_width="match_parent"
       android:layout_height="match_parent"
       android:scaleType="center"
       android:src="@drawable/ic_launcher"/>
</LinearLayout>

MyFragmentC.java

package com.exercise.AndroidNavigationTabs;

import android.app.Fragment;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;

public class MyFragmentC extends Fragment {

 @Override
 public View onCreateView(LayoutInflater inflater, ViewGroup container,
   Bundle savedInstanceState) {
  View myFragmentView = inflater.inflate(R.layout.fragment_c, container, false);
  return myFragmentView;
 }

}

/res/layout/fragment_c.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
   android:layout_width="fill_parent"
   android:layout_height="fill_parent"
   android:orientation="vertical" >
   <TextView
       android:layout_width="match_parent"
       android:layout_height="wrap_content"
       android:text="It's Fragment C" />

</LinearLayout>

Main code, AndroidNavigationTabsActivity.java

package com.exercise.AndroidNavigationTabs;

import android.app.ActionBar;
import android.app.ActionBar.Tab;
import android.app.Activity;
import android.app.Fragment;
import android.app.FragmentTransaction;
import android.os.Bundle;

public class AndroidNavigationTabsActivity extends Activity {
    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        
        final ActionBar actionBar = getActionBar();
        actionBar.setNavigationMode(ActionBar.NAVIGATION_MODE_TABS);
        
        Tab tabA = actionBar.newTab();
        tabA.setText("Tab A");
        tabA.setTabListener(new TabListener<MyFragmentA>(this, "Tag A", MyFragmentA.class));
        actionBar.addTab(tabA);
        
        Tab tabB = actionBar.newTab();
        tabB.setText("Tab B");
        tabB.setTabListener(new TabListener<MyFragmentB>(this, "Tag B", MyFragmentB.class));
        actionBar.addTab(tabB);
        
        Tab tabC = actionBar.newTab();
        tabC.setText("Tab C");
        tabC.setTabListener(new TabListener<MyFragmentC>(this, "Tag C", MyFragmentC.class));
        actionBar.addTab(tabC);
        
        if (savedInstanceState != null) {
            int savedIndex = savedInstanceState.getInt("SAVED_INDEX");
            getActionBar().setSelectedNavigationItem(savedIndex);
        }
        
    }

 @Override
 protected void onSaveInstanceState(Bundle outState) {
  // TODO Auto-generated method stub
  super.onSaveInstanceState(outState);
  outState.putInt("SAVED_INDEX", getActionBar().getSelectedNavigationIndex());
 }

 public static class TabListener<T extends Fragment> 
     implements ActionBar.TabListener{
     
        private final Activity myActivity;
        private final String myTag;
        private final Class<T> myClass;

        public TabListener(Activity activity, String tag, Class<T> cls) {
            myActivity = activity;
            myTag = tag;
            myClass = cls;
        }

  @Override
  public void onTabSelected(Tab tab, FragmentTransaction ft) {

   Fragment myFragment = myActivity.getFragmentManager().findFragmentByTag(myTag);
   
   // Check if the fragment is already initialized
         if (myFragment == null) {
             // If not, instantiate and add it to the activity
             myFragment = Fragment.instantiate(myActivity, myClass.getName());
             ft.add(android.R.id.content, myFragment, myTag);
         } else {
             // If it exists, simply attach it in order to show it
             ft.attach(myFragment);
         }
   
  }

  @Override
  public void onTabUnselected(Tab tab, FragmentTransaction ft) {
   
   Fragment myFragment = myActivity.getFragmentManager().findFragmentByTag(myTag);
   
   if (myFragment != null) {
             // Detach the fragment, because another one is being attached
             ft.detach(myFragment);
         }
   
  }

  @Override
  public void onTabReselected(Tab tab, FragmentTransaction ft) {
   // TODO Auto-generated method stub
   
  }
     
    }
}

Download the files.

Related:
- ViewPager