android - 再次替换根Fragment时，Fragment的ViewPager不显示其内容

Question

我正在实现包含 root view pager 的 fragment screen，其中包含 child fragment 和第一个 child fragment 有一个显示图像的 view pager。

第一次显示很好，但是当包含 root view pager 的 fragment 被删除并再次替换时(使用 fragment screen 的新关键字), roow view pager 不显示 child fragment。

这是我的源代码的一部分。

    @AfterViews // this is the method of fragment screen
    protected void afterViews() {
        api(HotelDetailAPI.class).getProduct("hotels", getArguments().getInt("itemId"), new Callback<Hotel>(this) {
            @Override
            public void success(Hotel _hotel, Response response) {
                hotel = _hotel;
                HotelDetailPagerAdapter adapter = new HotelDetailPagerAdapter(getFragmentManager());
                contentViewPager.setAdapter(adapter);
                contentViewPager.setBackgroundColor(0xffffff);
                super.success(hotel, response);
            }

            @Override
            public void failure(RetrofitError error) {
                super.failure(error);
                LOG.error("failed");
            }
        });
    }


private class HotelDetailPagerAdapter extends FragmentPagerAdapter {
        List<Fragment> fragments = new ArrayList<>();

        public HotelDetailPagerAdapter(FragmentManager fm) {
            super(fm);
            Bundle data = new Bundle();
            data.putSerializable("hotel", hotel);
            Fragment fragment1 = new HotelDetailReservationFragment_();
            Fragment fragment2 = new HotelDetailReservationFragment_();
            Fragment fragment3 = new HotelDetailReservationFragment_();
            fragment1.setArguments(data);
            fragment2.setArguments(data);
            fragment3.setArguments(data);
            fragments.add(fragment1);
            fragments.add(fragment2);
            fragments.add(fragment3);
        }

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

        @Override
        public int getCount() {
            return 3;
        }
    }


// this is the first fragment of root view pager it's not shown again.
@EFragment(R.layout.fragment_hotel_detail_reservation)
public class HotelDetailReservationFragment extends BaseFragment {
    private Hotel hotel;

    @AfterViews
    public void afterViews() {
        hotel = (Hotel)getArguments().getSerializable("hotel");
        FragmentTransaction ft = getBaseActivity().getFragmentManager().beginTransaction();
        Fragment fragment = new ImageSliderFragment_();
        Bundle data = new Bundle();
        data.putStringArray("images", hotel.getImages());
        fragment.setArguments(data);
        ft.add(R.id.hotel_detail_image_slider_container, fragment);
        ft.commit();
    }
}

注意fragment screen在用户按下返回键时从back stack中弹出，如果用户再次点击item，fragment screen的新实例被替换他们怎么了？

Answer 1

代替:

HotelDetailPagerAdapter adapter = new HotelDetailPagerAdapter(getFragmentManager());

试试:

HotelDetailPagerAdapter adapter = new HotelDetailPagerAdapter(getChildFragmentManager());

和

而不是:

FragmentTransaction ft = getBaseActivity().getFragmentManager().beginTransaction();

试试:

FragmentTransaction ft = getChildFragmentManager().beginTransaction();