Unable to instantiate Fragment

Question

Unable to instantiate fragment make sure class name exists, is public, and has an empty constructor that is public

Is it because my Fr

Answer 1

As CommonsWare said make it static or standalone, additionally don't know why you need a shedload of refactoring for getting findViewById to work. Suggestions:

Using the view inflated in onCreateView,

inflatedView.findViewById(.....)

or calling it in onActivityCreated(.....)

getActivity().findViewById(......)

But even if you still need a load of refactoring then that might just be the way it is, converting an app to use fragments doesn't come for free having just finished a project doing so.

Answer 2

public static class MyDialogFragment extends DialogFragment {

    public MyDialogFragment(){

    }

    public Dialog onCreateDialog(Bundle savedInstanceState) {
            LinearLayout main = new LinearLayout(getActivity());
    main.setOrientation(LinearLayout.VERTICAL);


            return (new AlertDialog.Builder(getActivity()).setTitle(
    getText("Title")).setView(main).create());
            }
 }

Answer 3

In my case, I was missing the constructor, the post from @eoghanm above helped me

public static class MyDialogFragment extends DialogFragment {

    public MyDialogFragment(){
    }
...
}

Answer 4

Make sure the Fragment isn't abstract. Copy&paste makes this kind of things happen :(

Answer 5

Using setRetainInstance(true) worked for us. Our inner classes now look like this:

public class SectionsPagerAdapter extends FragmentPagerAdapter {
    public SectionsPagerAdapter(FragmentManager fm) {
        super(fm);
    }

    @Override
    public Fragment getItem(int position) {
    // getItem is called to instantiate the fragment for the given page.
        Fragment fragment = new MySectionFragment();
        Bundle args = new Bundle();
        args.putInt(MySectionFragment.ARG_SECTION_NUMBER, position + 1);
        fragment.setArguments(args);
        fragment.setRetainInstance(true);
        return fragment;
    }
    // ...
}

public class MySectionFragment extends Fragment {
    public static final String ARG_SECTION_NUMBER = "section_number";
    @SuppressLint("ValidFragment")
    public MySectionFragment() {
    }
    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
        //...
    }       
    // ...
}

PS. Here's an interesting one about setRetainInstance(boolean): Understanding Fragment's setRetainInstance(boolean)

Answer 6

Hahah my hilarious issue was I had a call to getString() as a member level variable in my fragment which is a big no no because it's too early I guess. I wish the error was more descriptive!