Action bar menu items and Fragments

 How do we create menu items?
You can add menu items through code. But the easier method is writing an xml file in ../res/menu folder.

/res/menu/mymenu.xml

<menu xmlns:android="http://schemas.android.com/apk/res/android"
   
    >
    <item
        android:id="@+id/action_settings"
        android:icon="@android:drawable/some_icon"
        android:title="Customize"/>
     <item       
         android:id="@+id/action_settings"
        android:icon="@android:drawable/some_icon"
        android:title="Customize"/> 
</menu>

 Next  write the onCreateOptionsMenu() method of your fragment like this.

@Override
    public void onCreateOptionsMenu(Menu menu, MenuInflater inflater) {
        MenuInflater mnuInflater = getActivity().getMenuInflater();
        mnuInflater.inflate(R.menu.mymenu, menu);
        super.onCreateOptionsMenu(menu, inflater);
    }

Can Fragments add their own action bar menu items?

Yes, They can. To the existing items of activity, these extra menu items can be added by adding the line in the onCreate of the fragment

     setHasOptionsMenu(true);

How do we make the menu items appear on action bar always?

In the menu xml file add the option showAsAction="always"

              android:icon="..youricon"
        android:showAsAction="always"

How do we make the menu items appear on support action bar always?

In the menu xml file add the option compat:showAsAction="always"

              android:icon="..youricon"
        compat:showAsAction="always" 

And also add the line
xmlns:compat="http://schemas.android.com/apk/res-auto"  
to first element of xml file

That is 
<menu xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:compat="http://schemas.android.com/apk/res-auto"  >

What if fragment option items are not responding to click events

The onOptionItemSelected of fragment is executed after same method of parent activity and only if activity has not consumed it.  So make sure you return false in your activity method if itemid does not match. 

public class MyActivity extends Activity
{

.......
   @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        switch (item.getItemId()) {
        case R.id.action_show_offline_pages:
            .........
            return true;
        case R.id.somethingelse: do_something_else();
            return true;
        }
        return false;
    }
}

How do I change action bar items dynamically? 

Store the menuItem in the onCreateOptionsMenu() method as a global variable.


        MenuInflater inflater = this.getMenuInflater();
        inflater.inflate(R.menu.rsstitlemenu,menu);
        mCatMenuItem= menu.findItem(R.id.action_categories); 

Now make changes to it when necessary. 

void some_method(){
   mCatMenuItem.setVisible(false);
....
}