问题

I want to add in a fragment a tab with pagerview (scrollable).

    public class MyFragment extends Fragment {
    private FragmentTabHost tabHost;
    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
        tabHost = new FragmentTabHost(getActivity());
        tabHost.setup(getActivity(), getChildFragmentManager(), R.id.realtabcontent);
        tabHost.addTab(tabHost.newTabSpec("one").setIndicator("One"), OneFragment.class, null);
        tabHost.addTab(tabHost.newTabSpec("two").setIndicator("Two"), TwoFragment.class, null);
        return tabHost;
    }


    @Override
    public void onDestroyView(){
        super.onDestroyView();
        tabHost=null;
    }
}

With this layout

<?xml version="1.0" encoding="utf-8"?>
<android.support.v4.app.FragmentTabHost
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@android:id/tabhost"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <LinearLayout
        android:orientation="vertical"
        android:layout_width="match_parent"
        android:layout_height="match_parent">

        <android.support.v4.view.ViewPager
            android:id="@+id/realtabcontent"
            android:layout_width="match_parent"
            android:layout_height="0dp"
            android:layout_weight="1"/>

    </LinearLayout>
</android.support.v4.app.FragmentTabHost>

I tried several solutions, but do not work. I need to use fragment, not fragmentActivity. The code written up work.

回答1:

Used xml file like this:

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:orientation="vertical"
    android:layout_width="match_parent"
    android:layout_height="match_parent">


    <android.support.design.widget.TabLayout
        android:id="@+id/tabLayout"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:background="?attr/colorPrimary"
        app:tabGravity="fill"
        app:tabMode="fixed"
        app:tabMaxWidth="0dp"
        android:theme="@style/ThemeOverlay.AppCompat.Dark.ActionBar"/>

    <!-- View pager to swipe views -->
    <android.support.v4.view.ViewPager
        android:id="@+id/pager"
        android:layout_width="match_parent"
        android:layout_height="fill_parent"/>

</LinearLayout>

and your java file is here:

public class MyFragment extends Fragment {

    private View view;
    private TabLayout tabLayout;

    //This is our viewPager
    private ViewPager viewPager;

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

        view = inflater.inflate(R.layout.sticker_fragment, container, false);

        tabLayout = (TabLayout) view.findViewById(R.id.tabLayout);

        viewPager = (ViewPager) view.findViewById(R.id.pager);

        Viewpager adapter = new Viewpager(getActivity().getSupportFragmentManager(), getActivity());

        //Adding adapter to pager
        viewPager.setAdapter(adapter);


        tabLayout.setupWithViewPager(viewPager);
        tabLayout.setOnTabSelectedListener(new TabLayout.OnTabSelectedListener() {
            @Override
            public void onTabSelected(TabLayout.Tab tab) {
                viewPager.setCurrentItem(tab.getPosition());
            }

            @Override
            public void onTabUnselected(TabLayout.Tab tab) {

            }

            @Override
            public void onTabReselected(TabLayout.Tab tab) {

            }

            });

        return view;
    }



}

after that viewpager adapter is like this:

public class Viewpager extends FragmentStatePagerAdapter {

    final int PAGE_COUNT = 2;
    private String tabTitles[] = new String[]{"Local","Online"};
    private Context context;

    public Viewpager(FragmentManager fm, Context context) {
        super(fm);
        this.context = context;
    }

    @Override
    public Fragment getItem(int position) {
        switch (position){
            case 0:
                OneFragment oneFragment=new OneFragment();
                return oneFragment;
            case 1:
                TwoFragment twoFragment=new TwoFragment();
                return twoFragment;
            default:
                return null;
        }
    }

    @Override
    public int getCount() {
        return tabTitles.length;
    }

    @Override
    public CharSequence getPageTitle(int position) {

        return tabTitles[position];
    }

}

回答2:

Small Code for Tablayout + ViewPager

// find views by id
ViewPager vp= findViewById(R.id.viewpager);
TabLayout tl = findViewById(R.id.tablayout);

// attach tablayout with viewpager
tl.setupWithViewPager(vp);

ViewPagerAdapter adapter = new ViewPagerAdapter(getSupportFragmentManager());

// add your fragments
adapter.addFrag(new SampleFragment(), "Tab1");
adapter.addFrag(new SampleFragment(), "Tab2");
adapter.addFrag(new SampleFragment(), "Tab3");

// set adapter on viewpager
vp.setAdapter(adapter);

XML layout

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical">

    <com.google.android.material.tabs.TabLayout
        android:id="@+id/tablayout"
        android:layout_width="match_parent"
        android:layout_height="wrap_content" />

    <androidx.viewpager.widget.ViewPager
        android:id="@+id/viewpager"
        android:layout_width="match_parent"
        android:layout_height="0dp"
        android:layout_weight="1" />

</LinearLayout>

Note If you are not using AndroidX yet, you need to change following in layout.

Change com.google.android.material.tabs.TabLayout to android.support.design.widget.TabLayout
Chagne androidx.viewpager.widget.ViewPager to android.support.v4.view.ViewPager

But I'll strongly recommend to migrate to AndroidX, see @this answer to understand why.

And this is common ViewPagerAdapter for all your Viewpager in app.

public class ViewPagerAdapter extends FragmentStatePagerAdapter {
    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();
    }

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

    public void addFrag(Fragment fragment) {
        mFragmentList.add(fragment);
        mFragmentTitleList.add("");
    }

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