Android studio: how add tabs with ViewPager

Question

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

    public class MyFragment extends Fragment {
    private FragmentTabHost tabHost;
    @Override
         


        

Answer 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];
    }

}

Answer 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);
    }
}

If you need to set ViewPager in Fragment, please check @this answer.