Changing Fragments inside Activity through onListItemClick()

Question

I have this Activity which at first shows a Fragment with a list of elements. This works perfectly with this code:

@Override
protected void onCreate(Bundle savedInstanceState)
{
    super.onCreate(savedInstanceState);
    setContentView(R.layout.list_act);

    if(null == savedInstanceState)
    {
        FragmentManager fragmentManager = getFragmentManager();
        FragmentTransaction fragmentTransaction = fragmentManager.beginTransaction();
        ListFragment glfragment = new ListFragment();
        fragmentTransaction.add(R.id.listfrag1, glfragment);
        fragmentTransaction.commit();
    }

}

Well I have a ListFragment and a DetailFragment. But I don't know how to do the transition when I click an element of the list. I know the fragmentTransaction.replace(), but I don't know WHEN to call it.

I thought I should use the OnListItemClick() inside the ListFragment, but I don't know how to use the FragmentManager inside the Fragment and not in the main Activity... Also I want to "export" some data to the DetailFragment as if it was a Intent, but it's not.

Answer 1

To use the fragment manager inside your Fragment, simply call getActivity().getFragmentManager() instead of getFragmentManager(). Implementing this in your OnItemClickListener should suffice.

Answer 2

What I would do is:

• Define an interface with one method listItemSelected() with as an argument the id of the selected item
• Let your activity implement this interface
• In the onAttach of your list fragment, take the activity and keep it as a member variable, cast to the interface type. Make sure that in the onDetach you dereference it.
• In your onListItemClick, call this method on your activity
• In the activity, you can now do a new fragmenttransaction, this time you need to replace instead of add the fragment
• To create your detail fragment with the correct argument (the id), use the method described here.

This should normally work fine.