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我有以下应用程序结构：

- Activity (ViewPager tabs)
    - Fragment A -> Recyclerview with StaggeredGridLayoutManager
    - Fragment B -> Recyclerview with GridLayoutManager

问题：在后台保持几个小时后打开应用程序后，recyclerviewFragment A保持空白，但 recyclerviewFragment B 显示数据。两个recyclerviews 在它们的适配器中使用相同的arraylist 实例。

应用程序在短时间内最小化/恢复时不会出现问题。

我可以通过在开发人员选项中设置Background process limit来重现这一点。No background processes所以我的猜测是每次操作系统停止/终止进程时都会发生这种情况。

我正在使用一个扩展FragmentStatePagerAdapter为我的 ViewPager 适配器的类。

已经尝试过以下方法，但没有运气：

编辑1：在片段中A，如果我替换StaggeredGridLayoutManager为GridLayoutManager，它会显示数据。所以问题似乎出在StaggeredGridLayoutManager

编辑 2：附加代码（简化的类/变量名称以便于理解）

  • TabAdapter - viewpager 的适配器
public class TabAdapter extends FragmentStatePagerAdapter {
    private final List<Fragment> mFragmentList = new ArrayList<>();
    private final List<String> mFragmentTitleList = new ArrayList<>();

    public TabAdapter(FragmentManager fm) {
        super(fm);
    }

    @Override
    public Fragment getItem(int position) {
        return mFragmentList.get(position);
    }

    public void addFragment(Fragment fragment, String title) {
        mFragmentList.add(fragment);
        mFragmentTitleList.add(title);
    }

    @Nullable
    @Override
    public CharSequence getPageTitle(int position) {
        return mFragmentTitleList.get(position);
    }

    @Override
    public int getCount() {
        return mFragmentList.size();
    }
}
  • Activity - 包含 viewpager
public class MyActivity extends AppCompatActivity implements TabLayout.BaseOnTabSelectedListener {
    public static List<MyPojo> mylist = new ArrayList<>();
    private TabAdapter adapter;
    private TabLayout tabLayout;
    private ViewPager viewPager;
    private FragmentA fragmentA;
    private FragmentB fragmentB;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_landing);
        viewPager = findViewById(R.id.viewPager);
        tabLayout = findViewById(R.id.tabLayout);
        adapter = new TabAdapter(getSupportFragmentManager());
        mylist.add(...) // arraylist populated

        fragmentA = new FragmentA();
        fragmentB = new FragmentB();
        adapter.addFragment(fragmentA, "A");
        adapter.addFragment(fragmentB, "B");
        viewPager.setAdapter(adapter);
        tabLayout.setupWithViewPager(viewPager);
        tabLayout.addOnTabSelectedListener(this);
    }
    ... other methods
}
  • 片段 A - 具有交错网格布局
public class FragmentA extends Fragment {
    private RecyclerView mRecyclerView;
    private FragmentAAdapter adapter;

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
        View view = inflater.inflate(R.layout.fragment_a, container, false);
        mRecyclerView = view.findViewById(R.id.recycler_view_a);
        mRecyclerView.setLayoutManager(new StaggeredGridLayoutManager(2, 1));
        adapter = new FragmentAAdapter(getActivity(), MyActivity.myList);
        mRecyclerView.setAdapter(adapter);
        return view;
    }
    public void updateRecyclerViewData(){
        if (adapter != null)
            adapter.notifyDataSetChanged();
    }
    ... other methods
}
  • 片段 B - 带有网格布局
public class FragmentB extends Fragment {
    private RecyclerView mRecyclerView;
    private FragmentBAdapter adapter;
    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
        View view = inflater.inflate(R.layout.fragment_b, container, false);
        mRecyclerView = view.findViewById(R.id.recycler_view_b);
        mRecyclerView.setLayoutManager(new GridLayoutManager(getActivity(), 2));
        adapter = new FragmentBAdapter(getActivity(), MyActivity.myList);
        mRecyclerView.setAdapter(adapter);
        return view;
    }
    public void updateRecyclerViewData() {
        if (adapter != null)
            adapter.notifyDataSetChanged();
    }
    ... other methods
}
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