Anyway, the documentation covers all the things.
Once the activity is created, the
onCreateOptionsMenu()method is called only once, as described above. The system keeps and re-uses theMenuyou define in this method until your activity is destroyed. If you want to change the Options Menu any time after it's first created, you must override theonPrepareOptionsMenu()method. This passes you the Menu object as it currently exists. This is useful if you'd like to remove, add, disable, or enable menu items depending on the current state of your application.
E.g.
@Override
public boolean onPrepareOptionsMenu (Menu menu) {
if (isFinalized) {
menu.getItem(1).setEnabled(false);
// You can also use something like:
// menu.findItem(R.id.example_foobar).setEnabled(false);
}
return true;
}
On Android 3.0 and higher, the options menu is considered to always be open when menu items are presented in the action bar. When an event occurs and you want to perform a menu update, you must call invalidateOptionsMenu() to request that the system call onPrepareOptionsMenu().