在我的活动中,为了防止在配置更改中重新生成片段：

if(getSupportFragmentManager().findFragmentByTag(MAIN_TAB_FRAGMENT) == null) {
    getSupportFragmentManager().beginTransaction().replace(R.id.container,new MainTabFragment(),MAIN_TAB_FRAGMENT).commit();
}

片段代码B：

public class MainTabFragment extends Fragment {
 
    private PagerSlidingTabStrip mSlidingTabLayout;
    private LfPagerAdapter adapter;
    private ViewPager mViewPager;
 
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setRetainInstance(true);
    }
 
    @Nullable
    @Override
    public View onCreateView(LayoutInflater inflater,ViewGroup container,Bundle savedInstanceState) {
        return inflater.inflate(R.layout.fragment_tab,container,false);
    }
 
    @Override
    public void onViewCreated(View view,Bundle savedInstanceState) {
 
        this.adapter = new LfPagerAdapter(getChildFragmentManager());
 
        this.mViewPager = (ViewPager) view.findViewById(R.id.viewpager);
        this.mViewPager.setAdapter(adapter);
 
        this.mSlidingTabLayout = (PagerSlidingTabStrip) view.findViewById(R.id.sliding_tabs);
        this.mSlidingTabLayout.setViewPager(this.mViewPager);
    }
}

适配器代码：

public class LfPagerAdapter extends FragmentPagerAdapter {
 
    private static final int NUM_ITEMS = 3;
 
    private FragmentManager fragmentManager;
 
    public LfPagerAdapter(FragmentManager fm) {
        super(fm);
        this.fragmentManager = fm;
    }
 
    @Override
    public int getCount() {
        return NUM_ITEMS;
    }
 
    @Override
    public Fragment getItem(int position) {
        Log.d("TEST","TEST");
        switch (position) {
            case 1:
                return FragmentC.newInstance();
            case 2:
                return FragmentD.newInstance();
            default:
                return FragmentE.newInstance();
        }
    }
}

我的问题是,我无法保留视图寻呼机的状态,它的小孩片段的方向更改.

显然,这是每个轮回的要求：

this.adapter = new LfPagerAdapter(getChildFragmentManager());

这将导致整个寻呼机被重新创建,对吧？结果是

getItem(int position)

将会在每个轮播中被调用,片段将从头创建并丢失其状态：

return FragmentC.newInstance();

我试着解决这个问题：

if(this.adapter == null)
    this.adapter = new LfPagerAdapter(getChildFragmentManager());

在onViewCreated中,但是结果是旋转了被移除的寻呼机内的碎片.

任何想法如何正确保留传呼机内的状态？