Question

我尝试使用4个过滤器（组列表）实现ExpandableListView：

这个可扩展的列表在Fragment上，因为我想使用Master / Detail Flow模式。

当用户点击过滤器时，AsyncTask会调用Web服务来获取点击过滤器的关联元素。然后，在onPostExecute()方法中，我更新此可扩展列表的HashMap，然后，我执行notifySetDataChanged方法，但列表中没有数据：（

以下是代码的一些细节：

TreatmentExpandableListAdapter.java

public class TreatmentExpandableListAdapter extends BaseExpandableListAdapter {

private Context context;
private List<TreatmentState> treatmentStates;
private HashMap<TreatmentState, List<TreatmentSummary>> treatmentsByState;
private TreatmentExpandableListAdapter adapter;

...

@Override
public View getGroupView(int groupPosition, boolean b, View view, ViewGroup viewGroup) {
    currentState = treatmentStates.get(groupPosition);
    if (view == null) {
        LayoutInflater inflater = (LayoutInflater) context
                .getSystemService(Context.LAYOUT_INFLATER_SERVICE);
        view = inflater.inflate(R.layout.group_item,
                null);
    }
    TextView item = (TextView) view.findViewById(R.id.treatment_state);
    item.setTypeface(null, Typeface.BOLD);
    item.setText(currentState.toString());

    return view;
}

@Override
public View getChildView(int groupPosition, int childPosition, boolean b, View view, ViewGroup viewGroup) {
    final TreatmentState state = treatmentStates.get(groupPosition);
    final TreatmentSummary treatment = (TreatmentSummary) getChild(groupPosition, childPosition);
    LayoutInflater inflater = (LayoutInflater) context
            .getSystemService(Context.LAYOUT_INFLATER_SERVICE);

    if (view == null) {
        view = inflater.inflate(R.layout.fragment_treatment, null);
    }

    ImageView mStateView = (ImageView) view.findViewById(R.id.state);
    TextView mMedicineView = (TextView) view.findViewById(R.id.medicineName);
    TextView mInitDateView = (TextView) view.findViewById(R.id.initDate);
    TextView mEndDateView = (TextView) view.findViewById(R.id.endDate);

    mStateView.setImageResource(getImageByState(state));
    mMedicineView.setText(treatment.getMedicineName());
    mInitDateView.setText(treatment.getInitDate());
    mEndDateView.setText(treatment.getEndDate());

    return view;
}

...

TreatmentListFragment.java

public class TreatmentListFragment extends Fragment {

/* Parameter arguments, fragment initialization parameters */
private static final String PATIENT_ID = "patiendId";

/* Parameters */
private int mColumnCount = 1;
private long patientId;

ExpandableListView expListView;
TreatmentExpandableListAdapter expListAdapter;
List<TreatmentState> states;

/**
 * Mandatory empty constructor for the fragment manager to instantiate the
 * fragment (e.g. upon screen orientation changes).
 */
public TreatmentListFragment() {
}

@SuppressWarnings("unused")
public static TreatmentListFragment newInstance(long patientId) {
    TreatmentListFragment fragment = new TreatmentListFragment();
    Bundle args = new Bundle();
    args.putLong(PATIENT_ID, patientId);
    fragment.setArguments(args);
    return fragment;
}

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

    if (getArguments() != null) {
        patientId = getArguments().getLong(PATIENT_ID);
    }
    states = Arrays.asList(TreatmentState.values());
}

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
                         Bundle savedInstanceState) {
    View view = inflater.inflate(R.layout.fragment_treatment_list, container, false);

    expListView = (ExpandableListView) view.findViewById(R.id.treatment_list);
    expListAdapter = new TreatmentExpandableListAdapter(
            view.getContext(), states, DiaryAppHelper.getTreatmentsByState());
    expListView.setAdapter(expListAdapter);
    expListView.setOnGroupClickListener(new ExpandableListView.OnGroupClickListener() {
        @Override
        public boolean onGroupClick(ExpandableListView expandableListView, View view, int groupPosition, long id) {

            TextView tv = (TextView) view.findViewById(R.id.treatment_state);

            TreatmentState state = TreatmentState.getEnumByNameState(tv.getText().toString());
            new GetTreatmentsTask().execute(state.name());

            return true;
        }
    });

    return view;
}


@Override
public void onAttach(Context context) {
    super.onAttach(context);
    if (context instanceof OnListFragmentInteractionListener) {
        mListener = (OnListFragmentInteractionListener) context;
    } else {
        throw new RuntimeException(context.toString()
                + " must implement OnListFragmentInteractionListener");
    }
}

@Override
public void onDetach() {
    super.onDetach();
    mListener = null;
}


/**
 * This interface must be implemented by activities that contain this
 * fragment to allow an interaction in this fragment to be communicated
 * to the activity and potentially other fragments contained in that
 * activity.
 * <p/>
 * See the Android Training lesson <a href=
 * "http://developer.android.com/training/basics/fragments/communicating.html"
 * >Communicating with Other Fragments</a> for more information.
 */
public interface OnListFragmentInteractionListener {
    // TODO: Update argument type and name
    void onListFragmentInteraction(TreatmentSummary treatment);
}
 ...
}

GetTreatmentsTask

private class GetTreatmentsTask extends AsyncTask<String, Void, TreatmentSummary[]> {
    @Override
    protected TreatmentSummary[] doInBackground(String... params) {
        try {
            final String uri = getContext().getString(R.string.baseURL) + "/treatments_state?patientId=" + DiaryAppHelper.getCurrentUser().getUserAccountId() + "&state=" + params[0];

            RestTemplate rt = new RestTemplate();
            rt.getMessageConverters().add(new MappingJackson2HttpMessageConverter());

            ResponseEntity<TreatmentSummary[]> response = rt.getForEntity(uri, TreatmentSummary[].class);
            TreatmentSummary[] treatmentSummaries = response.getBody();

            return treatmentSummaries;
        } catch (Exception e) {
            Log.e("TreatmentExpandableList", e.getMessage(), e);
        }

        return null;
    }

    @Override
    protected void onPostExecute(TreatmentSummary[] treatmentSummariesArr) {
        if (treatmentSummariesArr != null && treatmentSummariesArr.length > 0) {
            TreatmentState state = treatmentSummariesArr[0].getState();
            Collections.addAll(expListAdapter.getTreatmentsByState().get(state), treatmentSummariesArr);


            getActivity().runOnUiThread(new Runnable() {
                public void run() {
                    expListAdapter.notifyDataSetChanged();
                }
            });

        }

    }

}

我做错了什么？任何帮助将不胜感激！

Answer 1

问题出在OnGroupClickListener()方法上。覆盖此方法时，collapseGroup和expandGroup方法未运行，因此未显示子项的数据。

更改此方法后，它可以正常工作：

expListView.setOnGroupClickListener(new ExpandableListView.OnGroupClickListener() {
        @Override
        public boolean onGroupClick(ExpandableListView expandableListView, View view, int groupPosition, long id) {

            TextView tv = (TextView) view.findViewById(R.id.treatment_state);

            TreatmentState state = TreatmentState.getEnumByNameState(tv.getText().toString());
            if (expandableListView.isGroupExpanded(groupPosition)) {
                expandableListView.collapseGroup(groupPosition);
            } else {
                new GetTreatmentsTask().execute(state.name());
                expandableListView.expandGroup(groupPosition);
            }

            return true;
        }
    });

片段中的ExpandableListView在AsyncTask之后不更新

1 个答案: