Android小部件RemoteViewsFactory的getViewAt（）方法随机调用

Question

我正在尝试在我的应用程序中实现小部件。该小部件将显示从Firebase获取的乐谱列表。 问题是在列表为空的getViewAt()之前调用onDataSetChanged()方法。 调用onDataSetChanged()之后，即使我用按钮强制刷新，也永远不会再次调用getViewAt()。

我该如何做？

我尝试了几种在线找到的解决方案，但似乎这里缺少某些东西。

这是我的课程，扩展了RemoteViewsFactory

public class WidgetDataProvider implements RemoteViewsService.RemoteViewsFactory {

    private List<Scores> scoresList = new ArrayList<>();
    String userId;
    DatabaseReference childNode;
    Context mContext;
    Intent intent;

    WidgetDataProvider(Context mContext, Intent intent) {
        this.mContext = mContext;
        this.intent = intent;
    }

    @Override
    public void onCreate() {
        initializeData();
    }

    @Override
    public void onDataSetChanged() {
        initializeData();
    }

    @Override
    public void onDestroy() {
        scoresList.clear();
    }

    @Override
    public int getCount() {
        return scoresList.size();
    }

    @Override
    public RemoteViews getViewAt(int index) {

        RemoteViews remoteViews = new RemoteViews(mContext.getPackageName(), R.layout.scores_widget_item);
        remoteViews.setTextViewText(R.id.tv_scores_widget_item, scoresList.get(index).getCategoryName());
        remoteViews.setTextViewText(R.id.tv_scores_widget_item_score, scoresList.get(index).getCategoryScore()* 10 + "%");

        return remoteViews;
    }

    @Override
    public RemoteViews getLoadingView() {
        return null;
    }

    @Override
    public int getViewTypeCount() {
        return 1;
    }

    @Override
    public long getItemId(int i) {
        return i;
    }

    @Override
    public boolean hasStableIds() {
        return false;
    }

    private void initializeData() throws NullPointerException {
        try {
            scoresList.clear();
            assert FirebaseAuth.getInstance().getCurrentUser() != null;
            userId = FirebaseAuth.getInstance().getCurrentUser().getUid();
            childNode = FirebaseDatabase.getInstance().getReference(DATA_SCORES).child(SCORES_BY_USER).child(userId);
            childNode.addValueEventListener(new ValueEventListener() {
                @Override
                public void onDataChange(@NonNull DataSnapshot dataSnapshot) {
                    for (final DataSnapshot category : dataSnapshot.getChildren()) {
                        scoresList.add(new Scores(userId, category.getKey(), Integer.parseInt(category.child(SCORE).getValue().toString())));
                    }
                }
                @Override
                public void onCancelled(@NonNull DatabaseError databaseError) {

                }
            });
        }catch (NullPointerException e){
            Log.d("firebase_exception", "initializeData: " + e.getMessage());
        }
    }
}