Fragment 中的 ActionBar 选项卡实现失败

ActionBar tab implementation fails in Fragment

Requirement:Fragment 应在通过 MainActivity

调用后提供 Actionbar 选项卡

Problem facing: 调用片段后,操作栏选项卡在显示 1-2 秒后变得不可见。

这是片段:

public class tabFragment extends Fragment implements ActionBar.TabListener{

SectionsPagerAdapter mSectionsPagerAdapter;

ViewPager mViewPager;

public static tabFragment newInstance() {
    return new tabFragment();
}

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

}


@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {



    View v = inflater.inflate(R.layout.testtab, container, false);
    mSectionsPagerAdapter = new SectionsPagerAdapter(
            getChildFragmentManager());

    mViewPager = (ViewPager) v.findViewById(R.id.pagerTest);
    mViewPager.setAdapter(mSectionsPagerAdapter);
    final ActionBar actionBar = ((MainActivity)getActivity()).getSupportActionBar();

    actionBar.setNavigationMode(ActionBar.NAVIGATION_MODE_TABS);
    mViewPager.setOnPageChangeListener(new ViewPager.SimpleOnPageChangeListener() {
        @Override
        public void onPageSelected(int position) {
            actionBar.setSelectedNavigationItem(position);
        }
    });

    // For each of the sections in the app, add a tab to the action bar.
    for (int i = 0; i < mSectionsPagerAdapter.getCount(); i++) {
        // Create a tab with text corresponding to the page title defined by
        // the adapter. Also specify this Activity object, which implements
        // the TabListener interface, as the callback (listener) for when
        // this tab is selected.
        actionBar.addTab(
                actionBar.newTab()
                        .setText(mSectionsPagerAdapter.getPageTitle(i))
                        .setTabListener(this));
    }

    return v;
}

@Override
public void onTabSelected(ActionBar.Tab tab, FragmentTransaction fragmentTransaction) {

    mViewPager.setCurrentItem(tab.getPosition());

}

@Override
public void onTabUnselected(ActionBar.Tab tab, FragmentTransaction fragmentTransaction) {

}

@Override
public void onTabReselected(ActionBar.Tab tab, FragmentTransaction fragmentTransaction) {

}
public class SectionsPagerAdapter extends FragmentPagerAdapter {

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

    @Override
    public Fragment getItem(int position) {
        // getItem is called to instantiate the fragment for the given page.
        // Return a PlaceholderFragment (defined as a static inner class below).
        return PlaceholderFragment.newInstance(position + 1);
    }

    @Override
    public int getCount() {
        // Show 3 total pages.
        return 3;
    }

    @Override
    public CharSequence getPageTitle(int position) {
        Locale l = Locale.getDefault();
        switch (position) {
            case 0:
                return getString(R.string.title_section1).toUpperCase(l);
            case 1:
                return getString(R.string.title_section2).toUpperCase(l);
            case 2:
                return getString(R.string.title_section3).toUpperCase(l);
        }
        return null;
    }
}

/**
 * A placeholder fragment containing a simple view.
 */
public static class PlaceholderFragment extends Fragment {
    /**
     * The fragment argument representing the section number for this
     * fragment.
     */
    private static final String ARG_SECTION_NUMBER = "section_number";

    /**
     * Returns a new instance of this fragment for the given section
     * number.
     */
    public static PlaceholderFragment newInstance(int sectionNumber) {
        PlaceholderFragment fragment = new PlaceholderFragment();
        Bundle args = new Bundle();
        args.putInt(ARG_SECTION_NUMBER, sectionNumber);
        fragment.setArguments(args);
        return fragment;
    }

    public PlaceholderFragment() {
    }

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        View rootView = inflater.inflate(R.layout.testtab1, container, false);
        return rootView;
    }
}

}

如何让 Actionbar 在 Fragment 中实现标签?我在 OnCreateView() 中实现了 getSupportActionBar。我被困在这里一整天。 有什么建议我在这里做错了吗?

NotePagerTabStrip 运行良好,但我想要 Actionbar 选项卡

Edit 我希望我的应用程序也支持 gingerbread

我建议使用来自 appcompat v21+ 的带有 slidingtablayout 的工具栏,以便于实施。