I have problem when I try to use fragment on screen rotate
My code is come from FragmentBasics on android training with Fragment, but I instead layout-large with layout-land
res/layout-land/activity_main.xml
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="horizontal"
android:baselineAligned="false" >
<fragment
android:id="@+id/headlines_fragment"
android:name="com.example.fragmentoverhoneycomb.HeadlinesFragment"
android:layout_width="0dp"
android:layout_height="match_parent"
android:layout_weight="1" />
<fragment
android:id="@+id/article_fragment"
android:name="com.example.fragmentoverhoneycomb.Articles"
android:layout_width="0dp"
android:layout_height="match_parent"
android:layout_weight="2" />
MainActivity
public class MainActivity extends Activity
implements OnHeadlineSelectedListener {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
if(findViewById(R.id.fragment_container) != null) {
if (savedInstanceState != null) {
return;
}
HeadlinesFragment firstFragment = new HeadlinesFragment();
firstFragment.setArguments(getIntent().getExtras());
getFragmentManager().beginTransaction().add(R.id.fragment_container, firstFragment).commit();
}
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main, menu);
return true;
}
@Override
public void onArticleSelected(int position) {
// TODO Auto-generated method stub
Articles articleFrag = (Articles) getFragmentManager().findFragmentById(R.id.article_fragment);
if (articleFrag != null) {
articleFrag.updateArticleView(position);
} else {
Articles newFragment = new Articles();
Bundle args = new Bundle();
args.putInt(Articles.ARG_POSITION, position);
newFragment.setArguments(args);
FragmentTransaction transaction = getFragmentManager().beginTransaction();
transaction.replace(R.id.fragment_container, newFragment);
transaction.addToBackStack(null);
transaction.commit();
}
}
Articles.java
public class Articles extends Fragment {
final static String ARG_POSITION = "position";
int mCurrentPosition = -1;
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
if (savedInstanceState != null) {
mCurrentPosition = savedInstanceState.getInt(ARG_POSITION);
}
return inflater.inflate(R.layout.activity_article, container, false);
}
@Override
public void onDestroyView() {
super.onDestroyView();
}
@Override
public void onStart() {
super.onStart();
Bundle args = getArguments();
if(args != null) {
updateArticleView(args.getInt(ARG_POSITION));
} else if (mCurrentPosition != -1) {
updateArticleView(mCurrentPosition);
}
}
public void updateArticleView(int position) {
TextView article = (TextView) getActivity().findViewById(R.id.textViewArticle);
article.setText(Ipsum.Articles[position]);
mCurrentPosition = position;
}
@Override
public void onSaveInstanceState(Bundle outState) {
super.onSaveInstanceState(outState);
outState.putInt(ARG_POSITION, mCurrentPosition);
}
}
So my idea is use single fragment when portrait and combine two fragment when landscape,
but I get a error when I do this:
Step.1 start with portrait state and show article_fragment via onArticleSelected once to show a article and then return to the HeadlinesFragment
Step.2 Ctrl-F11 twice (portrait -> landscape -> portrait)
Step.3 redo Step.1 then the error occurs:
Articles articleFrag = (Articles) getFragmentManager().findFragmentById(R.id.article_fragment);
return not null
when I debug this, I found the onCreateView() function didn't called when Step.3 occurrs