Java android片段选项卡（仅在轻扫时更改片段）不起作用单击选项卡名称

Question

我有一个活动，其中我有两个片段，当我在选项卡上滑动片段更改时，但是当我单击选项卡名称时，我的apk不会更改视图。我留在这些片段上。

这是我的活动：

public class ObjectListActivity extends  AppCompatActivity {

    private Toolbar toolbar;
    private TabLayout tabLayout;
    private ViewPager viewPager;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_object_list2);

        toolbar = (Toolbar) findViewById(R.id.toolbar);
        setSupportActionBar(toolbar);

        hideSoftKeyboard();

        android.support.v7.app.ActionBar actionBar = getSupportActionBar();
        actionBar.setNavigationMode(android.app.ActionBar.NAVIGATION_MODE_STANDARD);
        actionBar.setTitle("");
        getSupportActionBar().setDisplayHomeAsUpEnabled(false);

        viewPager = (ViewPager) findViewById(R.id.viewpager);
        setupViewPager(viewPager);

        tabLayout = (TabLayout) findViewById(R.id.tabs);
        tabLayout.setupWithViewPager(viewPager);
    }

    public void hideSoftKeyboard() {
        if(getCurrentFocus()!=null) {
            InputMethodManager inputMethodManager = (InputMethodManager) getSystemService(INPUT_METHOD_SERVICE);
            inputMethodManager.hideSoftInputFromWindow(getCurrentFocus().getWindowToken(), 0);
        }
    }

    private void setupViewPager(ViewPager viewPager) {
        ViewPagerAdapter adapter = new ViewPagerAdapter(getSupportFragmentManager());
        adapter.addFragment(new FragmentAllObjectActivity(), getString(R.string.all));
        adapter.addFragment(new FragmentGroupObjectsActivity(), getString(R.string.group));
        viewPager.setAdapter(adapter);
    }

    class ViewPagerAdapter extends FragmentPagerAdapter {
        private final List<Fragment> mFragmentList = new ArrayList<>();
        private final List<String> mFragmentTitleList = new ArrayList<>();

        public ViewPagerAdapter(FragmentManager manager) {
            super(manager);
        }

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

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

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

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

这是我的xml布局：

<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:background="@drawable/logowanie_tlo"
    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.v7.widget.Toolbar
        android:id="@+id/toolbar"
        android:layout_width="match_parent"
        android:layout_height="?attr/actionBarSize"
        app:layout_scrollFlags="scroll|enterAlways"
        />

    <android.support.design.widget.TabLayout
        android:id="@+id/tabs"
        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/viewpager"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        app:layout_behavior="@string/appbar_scrolling_view_behavior"  />
</android.support.design.widget.CoordinatorLayout>