When i call findFragmentById() with the id of my fragment, it return null. Let me show you the code.
The activity_main.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent">
<fragment android:name="com.madduck.test.app.fragment.MainFragment"
android:id="@+id/main_fragment"
android:layout_width="match_parent"
android:layout_height="match_parent" />
<fragment android:name="com.madduck.test.app.fragment.LoginFragment"
android:id="@+id/login_fragment"
android:layout_width="match_parent"
android:layout_height="match_parent" />
</LinearLayout>
The MainActivity.java
private static final int LOGIN = 0;
private static final int MAIN = 1;
private static final int FRAGMENT_COUNT = MAIN +1;
private Fragment[] fragments = new Fragment[FRAGMENT_COUNT]
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
FragmentManager fm = getSupportFragmentManager();
fragments[LOGIN] = fm.findFragmentById(R.id.login_fragment);
fragments[MAIN] = fm.findFragmentById(R.id.main_fragment);
FragmentTransaction transaction = fm.beginTransaction();
for (Fragment f : fragments) {
if (f != null)
transaction.hide(f);
else
Log.e(TAG, "???");
}
transaction.commit();
}
The thing is that when i call fm.findFragmentById(R.id.login_fragment);
I get null but when I call fm.findFragmentById(R.id.main_fragment);
I get the fragment.
The answer Kar0t is perfectly fine but this may help somebody. On my case I had a fragment inside of a fragment and I was getting the wrong FragmentManager. I just had to call:
getChildFragmentManager()
and then just find the Fragment as usual:
fm.findFragmentById(R.id.fragment)