Question

标题条指示所选选项卡在一次滑动时不会自动移动到下一个选项卡。它相应地移动到滑动手势，例如，如果你只是滑动一点，即使它指示相同的标签，它也会移动一点。

我想在片段中实现制表符布局，因为用户将从导航抽屉在此页面上导航。

Xml代码

<android.support.design.widget.CoordinatorLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:layout_width="match_parent"
android:layout_height="match_parent">

<android.support.design.widget.AppBarLayout
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:theme="@style/ThemeOverlay.AppCompat.Dark.ActionBar">

    <android.support.design.widget.TabLayout
        android:id="@+id/aboutTabs"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        app:tabMode="fixed"
        app:tabGravity="fill"/>

</android.support.design.widget.AppBarLayout>

<android.support.v4.view.ViewPager
    android:id="@+id/aboutViewPager"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    app:layout_behavior="@string/appbar_scrolling_view_behavior"  />

托管xml的代码

    public class AboutFragment extends Fragment{

    @BindView(R.id.aboutTabs)
    public TabLayout tabLayout;
    @BindView(R.id.aboutViewPager)
    public ViewPager viewPager;

    private View rootView;

    /**
     * Mandatory empty constructor for the fragment manager to instantiate the
     * fragment (e.g. upon screen orientation changes).
     */
    public AboutFragment() {
    }

    public static Fragment newInstance() {
        Fragment fragment = new AboutFragment();
        return fragment;
    }

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

        ButterKnife.bind(this, rootView);

        setupViewPager(viewPager);
        tabLayout.setupWithViewPager(viewPager);

        return rootView;
    }

    private void setupViewPager(ViewPager viewPager) {
        AboutPagerAdapter adapter = new AboutPagerAdapter(getChildFragmentManager());
        adapter.addFragment(new AboutUsFragment(), getResources().getString(R.string.str_about_us));
        adapter.addFragment(new MissionFragment(), getResources().getString(R.string.str_about_mission));
        adapter.addFragment(new ValuesFragment(), getResources().getString(R.string.str_about_values));
        viewPager.setAdapter(adapter);
    }

}

适配器

    public class AboutPagerAdapter extends FragmentPagerAdapter {

    private final List<Fragment> mFragmentList = new ArrayList<>();
    private final List<String> mFragmentTitleList = new ArrayList<>();

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

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

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

    @Override
    public int getCount() {
        return mFragmentList.size();
    }

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

导致此问题的原因是什么？我在哪里弄错了？提前致谢

Answer 1

如果片段为空，则会观察到此行为。所以只需在各自的片段中添加您的布局，它就可以解决问题。

标题条不会自动滚动到下一个标签，而是根据滑动手势的移动而移动

1 个答案: