android - Retain the Fragment object while rotating

Question

I have developed an app in Honeycomb and I am using fragments.
This is my app

• I have an Activity (Say A1) and in that there is a fragment
• Initially this fragment hold the object one fragment object say (F1)
• Then depending on the user actions it may change to other objects F2,F3 ....

What my problem is

When The user rotate the device the activity is recreated and which make F1 as the fragment object even though before rotating it wasn't
What is the way to retain the fragment object while rotating?
I used setRetainInstance(true); but it didn't work for me
And I have added the fragment by code in my onCreate function like this

@Override
public void onCreate(Bundle savedInstanceState) {
   super.onCreate(savedInstanceState);
   setContentView(R.layout.main);

   FragmentTransaction fragmentTransaction = getFragmentManager().beginTransaction();

   Fragment homeFragment = new Home();
   fragmentTransaction.add(R.id.mainFragement, homeFragment);
   fragmentTransaction.commit();
}

Answer 1

By default Android will retain the fragment objects. In your code you are setting the homeFragment in your onCreate function. That is why it is allways some homeFragment or fl what ever that you set in onCreate.

Because whenever you rotate, the onCreate will execute and set your fragment object to the first one

So the easy solution for you is check whether savedInstanceState bundle is null or not and set the fragment object

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

    if(null == savedInstanceState) {
        // set you initial fragment object 
    }
 }