How to get the fragment instance from the FragmentActivity?

Question

I set the content view in the FragmentActivity, and the activity will create the fragment instance for me according to the class name specified in the layout file. But how can I get that fragment instance?

public class MyActivity extends FragmentActivity {

    @Override
    protected void onCreate(Bundle extra) {
        super.onCreate(extra);
        setContentView(R.layout.page_fragment);
    }
}

layout/page_fragment.xml:

<?xml version="1.0" encoding="utf-8"?>
<fragment xmlns:android="http://schemas.android.com/apk/res/android"
  android:id="@+id/pageview"
  android:layout_width="match_parent"
  android:layout_height="match_parent"
  android:name="org.xi.android.PageFragment" />

Medarda

Answer 1

You can use use findFragmentById in FragmentManager.

Since you are using the Support library (you are extending FragmentActivity) you can use:

getSupportFragmentManager().findFragmentById(R.id.pageview)

If you are not using the support library (so you are on Honeycomb+ and you don't want to use the support library):

getFragmentManager().findFragmentById(R.id.pageview)

Please consider that using the support library is recommended even on Honeycomb+.

Permalloy

Please see my related question: #24834412 – Serpasil

this won't work if you have multiple instances of the frame fragment on the backstack. – Nikolaus

Answer 2

To get the fragment instance in a class that extends FragmentActivity:

MyclassFragment instanceFragment=
    (MyclassFragment)getSupportFragmentManager().findFragmentById(R.id.idFragment);

To get the fragment instance in a class that extends Fragment:

MyclassFragment instanceFragment =  
    (MyclassFragment)getFragmentManager().findFragmentById(R.id.idFragment);

Melise

'tis the right answer. The other (validated) answer doesn't work in the case of fragments using support library v4, as used in the question (FragmentActivity only present in support library) – Vaginismus