Question

I am working on my first android app so forgive me if this is a simple question. The app currently has five tabs (made using fragments) and I am currently trying to set up a ListFragment in the first tab.

In my MainActivity class I have the code:

public void onTabSelected(ActionBar.Tab tab, FragmentTransaction fragmentTransaction) {
    if (tab.getPosition() == 0) {
        TopRatedListFragment topRatedListFragment = new TopRatedListFragment();
        getSupportFragmentManager().beginTransaction().replace(R.id.container, topRatedListFragment).commit();
    } else {
        Fragment fragment = new DummySectionFragment();
        Bundle args = new Bundle();
        args.putInt(DummySectionFragment.ARG_SECTION_NUMBER, tab.getPosition() + 1);
        fragment.setArguments(args);
        getSupportFragmentManager().beginTransaction().replace(R.id.container, fragment).commit();
    }

Now this works fine for my “DummySectionFragment”s. But my TopRatedListFragment extends ListFragment instead of just Fragment… so therefore the above code is giving me issues.

The line:

getSupportFragmentManager().beginTransaction().replace(R.id.container, topRatedListFragment).commit();

is the one drawing the error and saying the .replace method doesn’t like the topRatedListedFragment argument since it is a ListFragment and not a regular Fragment.

How should I fix this?

Thanks!

Answer 1

Most likely, your imports and/or class definitions are messed up.

There are two implementations of Fragment, ListFragment, and FragmentTransaction. One set is in android.app. The other set is in android.support.v4.app. These are not compatible. You use the latter pair if you are using FragmentActivity for the Android Support package’s backport of fragments.

My guess is that your FragmentTransaction and your ListFragment are coming from different packages, one from android.app and one from android.support.v4.app. If so, you need to fix that, having both use the same package, whichever one is appropriate for your circumstances.