旋转手机时Android隐藏 fragment 内容

Question

在我的应用程序中，我使用支持 View 寻呼机和 PagerTabStrip。进入查看寻呼机我有一些 fragment ，进入其中一个我正在使用支持卡片 View 。运行应用程序后，所有卡片 View 项目都正确显示，但将手机从纵向旋转到横向后，内容隐藏。

更新: 主 Activity

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    ButterKnife.inject(this);
    Globals.setActivity(this);

    contentFragment = ContentFragment.newInstance(R.drawable.ic_launcher);
    getSupportFragmentManager().beginTransaction()
            .replace(R.id.frame_container, contentFragment)
            .commit();

    current_fragment_id = 0;
    updateFragment(current_fragment_id);

    drawer_adatper =
            new DrawerAdatper(
                    this, R.layout.drawer_item_layout, R.layout.drawer_item_group_layout, drawer_items);
    drawer_list.setAdapter(drawer_adatper);
}

ContentFragment fragment :

public class ContentFragment extends Fragment implements ScreenShotable {

    public static ContentFragment newInstance(int page) {
        ContentFragment fragmentFirst = new ContentFragment();
        Bundle          args          = new Bundle();
        args.putInt("page", page);
        fragmentFirst.setArguments(args);
        return fragmentFirst;
    }

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        page = getArguments().getInt("page", 0);
    }

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
        View view = inflater.inflate(R.layout.fragment_online_categories, container, false);
        ButterKnife.inject(this, view);
        initializeUi();
        pager_header.setTabIndicatorColor(Color.parseColor(Arrays.asList(pageTabIndicatorColors).get(0)));
        BootStrapPagerAdapter adapterViewPager = new BootStrapPagerAdapter(getActivity().getSupportFragmentManager());
        return view;
    }

    public static class BootStrapPagerAdapter extends FragmentPagerAdapter {
        private static int NUM_ITEMS = 8;
        public BootStrapPagerAdapter(FragmentManager fragmentManager) {
            super(fragmentManager);
        }

        public int getCount() {
            return NUM_ITEMS;
        }
        @Override
        public Fragment getItem(int position) {
            switch (position) {
                case 0:
                    return FragmentContactList.newInstance(0);
            }
        }
        @Override
        public CharSequence getPageTitle(int position) {
            String title = "";
            switch (position) {
                case 0:
                    title = Utils.getString(R.string.section_industry);
                    break;
            }
            return title;
        }
    }
}

FragmentContactList:

public class FragmentContactList extends Fragment {
    private StackTraceElement[] traceElements = Thread.currentThread().getStackTrace();
    private int page;
    RecyclerView rv;
    private List<Person> persons;

    public static FragmentContactList newInstance(int page) {
        FragmentContactList fragmentFirst = new FragmentContactList();
        Bundle              args          = new Bundle();
        args.putInt("page", page);
        fragmentFirst.setArguments(args);
        return fragmentFirst;
    }

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        page = getArguments().getInt("page", 0);
    }

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
        View view = inflater.inflate(R.layout.recyclerview_activity, container, false);
        rv = (RecyclerView) view.findViewById(R.id.rv);

        LinearLayoutManager llm = new LinearLayoutManager(getActivity());
        rv.setLayoutManager(llm);
        rv.setHasFixedSize(true);

        initializeData();
        initializeAdapter();
        return view;
    }

    private void initializeData(){
        persons = new ArrayList<>();
        persons.add(new Person("Emma Wilson", "23 years old", R.drawable.icon_inbox));
        persons.add(new Person("Lavery Maiss", "25 years old", R.drawable.icon_inbox));
        persons.add(new Person("Lillie Watts", "35 years old", R.drawable.icon_inbox));
    }

    private void initializeAdapter(){
        RVAdapter adapter = new RVAdapter(persons);
        rv.setAdapter(adapter);
    }
    @Override
    public void onResume() {
        super.onResume();
        getView().invalidate();
    }
}

Answer 1

你应该改变

public static class BootStrapPagerAdapter extends FragmentPagerAdapter

到

public static class BootStrapPagerAdapter extends FragmentStatePagerAdapter

您可以从这里检查它们之间的区别: Difference between FragmentPagerAdapter and FragmentStatePagerAdapter