android - Hide/Show Action Bar Option Menu Item for different fragments

Question

I have a Sherlock Fragment Activity in which there are 3 Fragments.

Fragment A, Fragment B, Fragment C are three fragments. I want to show a done option menu in Fragment B only.

And the activity is started with Fragment A. When Fragment B is selected done button is added.

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setHasOptionsMenu(true);
}

@Override
public void onCreateOptionsMenu(Menu menu, MenuInflater inflater) {
    if(!menusInflated){
        inflater.inflate(R.menu.security, menu);
        menusInflated=true;
    }

    super.onCreateOptionsMenu(menu, inflater);
}

When I again start Fragment A I want to options Menu DONE (which was set at Fragment B) for this I am doing like this

setHasOptionsMenu(false);
MenuItem item = (MenuItem) menu.findItem(R.id.done_item);
item.setVisible(false);

But this is not hiding at all, also it is giving NullPointerException when Activity if first started with Fragment A.

Please let me know what is the problem.

Answer 1

Try this...

You don't need to override onCreateOptionsMenu() in your Fragment class again. Menu items visibility can be changed by overriding onPrepareOptionsMenu() method available in Fragment class.

 @Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setHasOptionsMenu(true);
}
@Override
public void onPrepareOptionsMenu(Menu menu) {
    menu.findItem(R.id.action_search).setVisible(false);
    super.onPrepareOptionsMenu(menu);
}