Fragment garbage collection issue

I'm writing an app where I'm using fragments, and I'm seeing a really confusing behavior in my DDMS heap dumps: When I initially run my application, let's say there are a couple of fragments in the stack:

HomeFragment: 1
WelcomeFragment: 1
SignInFragment: 1
CreateAcctFragment: 1

The immediate dominator for each of these is .

Th开发者_StackOverflow中文版en I rotate the screen. I now get:

HomeFragment: 2
WelcomeFragment: 2
SignInFragment: 2
CreateAcctFragment: 2

Now the immediate dominators for each instance are for one and android.support.v4.app.FragmentManagerImpl for the other.

I initially thought I had a memory leak, that one of my fragments was not being garbage collected, as that had happened to me before. However, in that case every time I rotated the screen I added one more instance of each. Now no matter how many times I rotate the screen, I "only" see 2 instances of each.

Any thoughts/suggestions?

---

You should only instantiate the fragments if your activity onCreate() method is not passed a bundle. The android framework will instantiate them for you if a bundle is passed to onCreate().

This is the example of Activity.onCreate from fragment docs: http://developer.android.com/guide/topics/fundamentals/fragments.html

public static class DetailsActivity extends Activity {

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

        if (getResources().getConfiguration().orientation
                == Configuration.ORIENTATION_LANDSCAPE) {
            // If the screen is now in landscape mode, we can show the
            // dialog in-line with the list so we don't need this activity.
            finish();
            return;
        }

        if (savedInstanceState == null) {
            // During initial setup, plug in the details fragment.
            DetailsFragment details = new DetailsFragment();
            details.setArguments(getIntent().getExtras());
            getFragmentManager().beginTransaction().add(android.R.id.content, details).commit();
        }
    }
}