TabLayout和Viewpager片段中的动态数据不同步

Question

我有一个TabLayout，其中的数据是从包含{"TOPS","LAUNDRY","BEDDING"...}的网络服务中填充的。

此数据存储在传递到适配器的列表中。

myTabAdapter = new MyTabAdapter(getSupportFragmentManager(),tabListings);
viewpager.setAdapter(myTabAdapter);
tabList.setupWithViewPager(viewpager);

我的TabAdapter。

public class MyTabAdapter extends FragmentStatePagerAdapter {

    private ArrayList<TabListing> tabListings;
    String item;
    private Bundle bundle;

    public MyTabAdapter(FragmentManager supportFragmentManager, ArrayList<TabListing> tabListings) {
        super(supportFragmentManager);
        this.tabListings = tabListings;
    }

    @Override
    public Fragment getItem(int position) {
            TabListing l = tabListings.get(position);
            String a = l.getName();
            bundle = new Bundle();
            bundle.putString("item", a);
            return OneFragment.newInstance(0, bundle);
    }

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

    @Nullable
    @Override
    public CharSequence getPageTitle(int position) {
            TabListing l = tabListings.get(position);
            String a = l.getName();
        return a;
    }
}

在getItem()方法中，我使用bundle将片段传递给使用新实例方法的片段。

当数据进入像“TOPS”这样的片段时，它将在Firebase的数据库参考字段中传递，以填充我的recyclerview。

我的问题是当我运行应用程序时，在第一次运行中获取“LAUNDRY”而不是“TOPS”的数据。当我将2索引向前滑动到“BEDDING”时，数据将根据选项卡同步。我无法理解这是什么问题。

我的片段课。

public class OneFragment extends Fragment {

    private static String a;
    RecyclerView recyclerview;
    AdapterToActivity act;
    Bundle args;
    ListingAdapter adapter;
    FirebaseDatabase mDatabase;
    DatabaseReference mReference;
    ContentLoadingProgressBar pBar;
    int position;
    ArrayList<ItemList> itm = new ArrayList<>();

    public OneFragment() {
    }

    public static OneFragment newInstance(int position, Bundle item) {
        Bundle args = item;
        a = args.getString("item");
        OneFragment fragment = new OneFragment();
        fragment.setArguments(args);
        return fragment;
    }

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        View v = inflater.inflate(R.layout.fragment_one, container, false);
        recyclerview = v.findViewById(R.id.all_product_list);
        pBar = v.findViewById(R.id.progress);
        RecyclerView.LayoutManager layoutManager = new GridLayoutManager(getActivity(), 1);
        recyclerview.setLayoutManager(layoutManager);
        adapter = new ListingAdapter(getActivity(),itm,a);
        args = getArguments();
        RecyclerViewAdapterMethod();
        return v;
    }

    @Override
    public void onStart() {
        super.onStart();
        pBar.show();

        adapter.notifyDataSetChanged();
        pBar.hide();
    }

    private void RecyclerViewAdapterMethod() {
        pBar.show();
        mDatabase = FirebaseDatabase.getInstance();
        mReference = mDatabase.getReference(a);
        mReference.addChildEventListener(new ChildEventListener() {
            @Override
            public void onChildAdded(DataSnapshot dataSnapshot, String s) {
                ItemList l;
                l = dataSnapshot.getValue(ItemList.class);
                itm.add(l);
                recyclerview.setAdapter(adapter);
                adapter.notifyDataSetChanged();
                pBar.hide();
                }

            @Override
            public void onChildChanged(DataSnapshot dataSnapshot, String s) {
            }

            @Override
            public void onChildRemoved(DataSnapshot dataSnapshot) {

            }

            @Override
            public void onChildMoved(DataSnapshot dataSnapshot, String s) {

            }

            @Override
            public void onCancelled(DatabaseError databaseError) {

            }
        });
    }
}