片段内容在我切换并再次选择之前不会显示

Question

I've got a problem with my Android app: my fragment content doesn't show up until I switch it and I select it again. What should load just at the fragment start is a list of Cards.

Here you got the onCreate method of the Fragment that loads everything:

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    bundle = this.getArguments();
    debts = bundle.getParcelableArrayList("list");
    adapter =  new CardAdapter(getActivity(), android.R.color.holo_blue_dark);

    for (int i=0; i<debts.size();++i) {
        Debt d = debts.get(i);
        Card card = new Card(d.getSecondUser(),d.getSubject());
        adapter.add(card);
    }


}

And here the onActivityCreated method where i set the adapter for the list:

@Override
public void onActivityCreated(Bundle savedInstanceState) {
    super.onActivityCreated(savedInstanceState);

    CardListView list = (CardListView) getView().findViewById(R.id.newCard);
    list.setCardTheme(CardTheme.Light);
    list.setAdapter(adapter);
}

It works if I use an ArrayList of Cards already loaded, but not this way. I tried nearly everything... thank you very much.

---

UPDATE: Even I tried with the solutions you gave me, it keeps happening, my code now:

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    bundle = this.getArguments();
    debts = bundle.getParcelableArrayList("list");
    adapter =  new CardAdapter(getActivity(), android.R.color.holo_blue_dark);

    for (int i=0; i<debts.size();++i) {
        Debt d = debts.get(i);
        Card card = new Card(d.getSecondUser(),d.getSubject());
        adapter.add(card);
    }


}

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
                         Bundle savedInstanceState) {

    View rootView = inflater.inflate(R.layout.fragment_debts, container,
            false);

    CardListView list = (CardListView) rootView.findViewById(R.id.newCard);
    list.setCardTheme(CardTheme.Light);
    list.setAdapter(adapter);

    return rootView;
}

Answer 1

You should initialize your cardListView inside the onCreateView() method. onCreateView() gets called before the onActivityCreated() method. onCreateView() should be the point when the view of your fragment is initialized.

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
            Bundle savedInstanceState) {

    //use your layout file instead of R.layout.fragment_main
    View rootView = inflater.inflate(R.layout.fragment_main, container,
                false);

    CardListView list = rootView.findViewById(R.id.newCard);
    list.setCardTheme(CardTheme.Light);
    list.setAdapter(adapter);
}

Please take a look at the lifecycle of Fragments .