Question

我正在尝试为我的一个片段中的ListView设置适配器。但是，我收到一个空指针错误，我不知道什么是错的。

public class OptionsFragment extends Fragment{

    ArrayAdapter<String> adapter;
    //ArrayAdapter<String> adapter1 = ArrayAdapter.createFromResource

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

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

        ListView cListView = (ListView) rootView.findViewById(R.id.currencyListView);
        String[] test = {"1", "2", "3", "4", "5", "6", "7", "8", "9", "10"};
        adapter = new ArrayAdapter<String>(this.getActivity(), android.R.layout.simple_list_item_1, test);

        //View v = inflater.inflate(R.layout.optionsfragmentnew, container, false);
        cListView = (ListView) rootView.findViewById(android.R.id.list);
        cListView.setAdapter(adapter);

        return rootView;
    }
}

Answer 1

在onActivityCreated()方法期间设置适配器，而不是在onCreateView()期间设置适配器。

Answer 2

我希望此代码可以帮助您

public class OptionsFragment extends Fragment {

ListView list;

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
        Bundle savedInstanceState) {
    return inflater.inflate(R.layout.activity_main, container, false);
}

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

    list = (ListView) getActivity().findViewById(R.id.list);
    String[] test = {"1", "2", "3", "4", "5", "6", "7", "8", "9", "10"};
    ArrayAdapter adapter = new ArrayAdapter<String>(this.getActivity(), android.R.layout.simple_list_item_1, test);
    list.setAdapter(adapter);

}

}

设置适配器时的nullpointer

2 个答案: