AsyncTask在onCreateView（）之前未更新TableLayout

Question

我正在制作一个测验应用程序，可以向用户显示一张具有先前测验结果的表格。我正在尝试用AsyncTask填充表，但问题是onCreateView（）方法在AsyncTask之前完成，所以我得到了一个空表。我已经能够在不使用AsyncTask的情况下动态添加行，所以我确定问题出在我使用该类的方式上。这是应用程序这一部分的片段：

public class GalleryFragment extends Fragment {

    private GalleryViewModel galleryViewModel;
    private QuizAppData quizAppData;
    private List<QuizResults> resultsList;
    private TableLayout table;
    private QuizResultsReader reader;

    public TableRow addNewEntry(Context context, String user, String date, String score) {

        QuizHistoryTableRow row = new QuizHistoryTableRow(context, user, date, score);
        row.setLayoutParams(new TableRow.LayoutParams(TableRow.LayoutParams.MATCH_PARENT, TableRow.LayoutParams.WRAP_CONTENT));
        return row;
    }

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

        View root = getLayoutInflater().inflate(R.layout.fragment_gallery, null, false);

        table = root.findViewById(R.id.quiz_history_table);

        quizAppData = new QuizAppData(getContext());
        reader = new QuizResultsReader();
        reader.execute(getContext());
    }

    public View onCreateView(@NonNull LayoutInflater inflater,
                             ViewGroup container, Bundle savedInstanceState) {
        View root = inflater.inflate(R.layout.fragment_gallery, container, false);
        return root;
    }

    private class QuizResultsReader extends AsyncTask<Context,Void,Void> {

        @Override
        protected Void doInBackground(Context... context) {
            android.os.Debug.waitForDebugger();
            openAppData();
            return null;
        }

        @Override
        protected void onPostExecute(Void aVoid) {
            super.onPostExecute(aVoid);
            final String DEBUG_TAG = "onPostExecute";
            populateTable();
            Log.d( DEBUG_TAG, " QuizResults retrieved");

        }
    }

    public void openAppData() {
        android.os.Debug.waitForDebugger();
        String TAG = "QuizResults reader";
        try {
            quizAppData.open();
            resultsList = quizAppData.retrieveAllQuizResults();
        }
        catch (Exception e){
            Log.e(TAG,e.toString());
        }
    }

    public void populateTable() {
        String user, date, score;

        for (QuizResults results: resultsList) {
            user = results.getUsername();
            date = results.getDate();
            score = results.getResult();

            TableRow row = addNewEntry(getContext(), user, date, score);
            table.addView(row, new TableLayout.LayoutParams(TableLayout.LayoutParams.MATCH_PARENT, TableLayout.LayoutParams.WRAP_CONTENT));
        }

        TableRow row = addNewEntry(getContext(), "user", "date", "score");
        table.addView(row, new TableLayout.LayoutParams(TableLayout.LayoutParams.MATCH_PARENT, TableLayout.LayoutParams.WRAP_CONTENT));

        quizAppData.close();
    }

}

我已尝试在onCreateView方法中使用AsyncTask.get()以确保任务已完成，但这会导致应用程序冻结。在这个问题上的任何帮助将不胜感激。

Answer 1

在onViewCreated()中执行AsyncTask调用。在onViewCreated()方法中移动以下几行：

        quizAppData = new QuizAppData(getContext());
        reader = new QuizResultsReader();
        reader.execute(getContext());

并在table中初始化onCreateView ()对象>>