PagerAdapter不附加到ViewPager

Question

我具有以下视图结构：

<RecyclerView>

    <CardView>
        <RecyclerView id:="inner_recycler">
        </RecyclerView>
    </CardView>

    <CardView>
        <ViewPager id:="pager_1">
        </ViewPager>
    </CardView>

    <CardView>
        <ViewPager id:="pager_2">
        </ViewPager>
    </CardView>

    <CardView>
        <ViewPager id:="pager_3">
        </ViewPager>
    </CardView>

</RecyclerView>

RecyclerView适配器：

public class TodayStatsAdapter extends RecyclerView.Adapter<RecyclerView.ViewHolder> {

    private Map<Date, StatsBean> mStats;
    private Context mContext;

    public TodayStatsAdapter(Context context, Map<Date, StatsBean> stats) {
        mStats = stats;
        mContext = context;
    }

    @Override
    public int getItemViewType(int position) {
        if (position > 0) {
            return R.layout.today_stats_other_item;
        } else {
            return R.layout.today_stats_first_item;
        }
    }

    @NonNull
    @Override
    public RecyclerView.ViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
        View view = LayoutInflater.from(parent.getContext()).inflate(viewType, parent, false);
        if (R.layout.today_stats_first_item == viewType) {
            return new TodayFirstStatsHolder(view);
        } else {
            return new TodayOtherStatsHolder(view, mContext);
        }
    }

    @Override
    public void onBindViewHolder(@NonNull RecyclerView.ViewHolder holder, int position) {
        List<Date> listDate = new ArrayList<>(mStats.keySet());
        Collections.sort(listDate, Date::compareTo);

        if (holder instanceof TodayFirstStatsHolder) {
            TodayFirstStatsHolder viewHolder = (TodayFirstStatsHolder) holder;
            final Date lastDate = listDate.get(listDate.size() - 1);
            final StatsBean bean = mStats.get(lastDate);
            viewHolder.setDateTime(mContext.getString(R.string.stats_today_text)+ " " + lastDate.getHours() + ":" + lastDate.getMinutes());
            viewHolder.initRecycler(bean);
        }

        if (holder instanceof TodayOtherStatsHolder) {
            TodayOtherStatsHolder viewHolder = (TodayOtherStatsHolder) holder;
            final Date lastDate = listDate.get(position - 1);
            final StatsBean bean = mStats.get(lastDate);
            viewHolder.setDateTime(mContext.getString(R.string.stats_today_text)+ " " + lastDate.getHours() + ":" + lastDate.getMinutes());
            viewHolder.initPager(bean);
        }
    }

    @Override
    public int getItemCount() {
        return mStats.size();
    }

    public static class TodayFirstStatsHolder extends RecyclerView.ViewHolder {

        private TextView mItemDateText;
        private RecyclerView mItemRecyclerView;
        private Context mContext;

        public TodayFirstStatsHolder(@NonNull View itemView) {
            super(itemView);
            mContext = itemView.getContext();
            mItemDateText = itemView.findViewById(R.id.first_item_date_text);
            mItemRecyclerView = itemView.findViewById(R.id.first_item_recycler_view);
        }

        public void setDateTime(String dateTime) {
            mItemDateText.setText(dateTime);
        }

        public void initRecycler(StatsBean bean) {
            RecyclerView.LayoutManager layoutManager = new LinearLayoutManager(mContext) {
                @Override
                public boolean canScrollVertically() {
                    return false;
                }
            };
            mItemRecyclerView.setLayoutManager(layoutManager);
            mItemRecyclerView.setHasFixedSize(true);
            TodayStatsFirstItemAdapter adapter = new TodayStatsFirstItemAdapter(bean, mContext);
            mItemRecyclerView.setAdapter(adapter);
        }
    }

    public static class TodayOtherStatsHolder extends RecyclerView.ViewHolder {

        private TextView mItemDateText;
        private ViewPager mItemViewPager;
        private Context mContext;


        public TodayOtherStatsHolder(@NonNull View itemView, Context context) {
            super(itemView);
            mContext = context;
            mItemDateText = itemView.findViewById(R.id.first_item_date_text);
            mItemViewPager = itemView.findViewById(R.id.other_item_pager);
            mItemViewPager.setVisibility(View.VISIBLE);
        }

        public void setDateTime(String dateTime) {
            mItemDateText.setText(dateTime);
        }

        public void initPager(StatsBean bean) {
            TodayStatsOtherItemPagerAdapter pagerAdapter = new TodayStatsOtherItemPagerAdapter(
                    ((MainActivity) mContext).getSupportFragmentManager(),
                    bean.getStats()
            );
            mItemViewPager.setAdapter(pagerAdapter);
        }
    }
}

PagerAdapter：

public class TodayStatsOtherItemPagerAdapter extends FragmentStatePagerAdapter {

    private final List<Map.Entry<String, Integer>> mEntriesStats;

    public TodayStatsOtherItemPagerAdapter(FragmentManager fm, Map<String, Integer> stats) {
        super(fm);
        mEntriesStats = new ArrayList<>(stats.entrySet());
    }

    @Override
    public Fragment getItem(int position) {
        return TodayStatsPagerFragment.newInstance(mEntriesStats.get(position));
    }

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

}

第一个RecyclerView具有一个适配器，该适配器可使用RecyclerView或ViewPager创建CardView。内部的RecyclerView正在初始化并正常工作。每个ViewPagers都有自己的PagerAdapters和ViewHolders。 “ pager_1”正在正常创建和膨胀，但是其他寻呼机未连接自己的适配器，因此不会显示信息。适配器为什么会表现出这种行为？每个ViewPager如何附加自己的适配器？

对不起，我的英语不好。我希望你能帮助我。