I have simple app with fragments.
At the beginning list of fragments is empty.
And there are 2 buttons:
ADD FRAGMENT
REMOVE FRAGMENT
And following use-case:
- Add fragment
- Add fragment
- Remove first fragment
- Add fragment
As result onCreateView() on 4th step is not executed.
If I add fragment again on 5th step - onCreateView is executed again.
Why is it so? I didn't find right answer in google.
Source code:
public class MyActivity extends FragmentActivity {
private ViewPager pager;
private FragmentAdapter adapter;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
pager = (ViewPager) findViewById(R.id.pager);
final Button addButton = (Button) findViewById(R.id.add_button);
addButton.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
adapter.addFragment(new MyFragment());
adapter.notifyDataSetChanged();
}
});
final Button removeButton = (Button) findViewById(R.id.remove_button);
removeButton.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
adapter.removeFragment(0);
adapter.notifyDataSetChanged();
}
});
adapter = new FragmentAdapter(getSupportFragmentManager());
pager.setAdapter(adapter);
pager.setOffscreenPageLimit(10);
}
private class FragmentAdapter extends FragmentStatePagerAdapter {
final List<MyFragment> fragments = new ArrayList<MyFragment>();
public FragmentAdapter(FragmentManager fm) {
super(fm);
}
@Override
public Fragment getItem(int i) {
return fragments.get(i);
}
@Override
public int getCount() {
return fragments.size();
}
public void addFragment(MyFragment fragment) {
fragments.add(fragment);
}
public void removeFragment(int index) {
fragments.remove(index);
}
}
private class MyFragment extends Fragment {
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
return inflater.inflate(R.layout.fragment, container, false);
}
}
}
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"
>
<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Add"
android:id="@+id/add_button"/>
<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Remove first"
android:id="@+id/remove_button"/>
<android.support.v4.view.ViewPager
android:id="@+id/pager"
android:layout_width="match_parent"
android:layout_height="match_parent"/>
</LinearLayout>
fragment.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="match_parent">
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="New Text"
android:id="@+id/textView"
android:layout_gravity="center_horizontal"/>
</LinearLayout>
