PagerTabStrip In android studio

Content_main.xml

<android.support.v4.view.ViewPager xmlns:android="http://schemas.android.com/apk/res/android"

    xmlns:tools="http://schemas.android.com/tools"

    android:id="@+id/pager"

    android:layout_width="match_parent"  

    android:layout_height="match_parent"

    tools:context="nc.example.com.pagertabstrip.MainActivity"

    tools:showIn="@layout/activity_main">

    <android.support.v4.view.PagerTabStrip

        android:layout_width="match_parent"

        android:layout_height="wrap_content"

        android:layout_gravity="top"/>

</android.support.v4.view.ViewPager>

Fragment_Page_Layout.xml

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"

    xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent"

    android:layout_height="match_parent" android:paddingLeft="@dimen/activity_horizontal_margin"

    android:paddingRight="@dimen/activity_horizontal_margin"

    android:paddingTop="@dimen/activity_vertical_margin"

    android:paddingBottom="@dimen/activity_vertical_margin"

    >

    <TextView android:id="@+id/page_number_label"

        android:layout_width="match_parent"

        android:layout_height="wrap_content"

        android:textAppearance="@android:style/TextAppearance.Large"

        android:gravity="center"

        android:layout_centerVertical="true" />

</RelativeLayout>

Mainactivity.java

package nc.example.com.pagertabstrip;

import android.os.Bundle;

import android.support.v4.view.ViewPager;

import android.support.v7.app.AppCompatActivity;

public class MainActivity extends AppCompatActivity {

    @Override

    protected void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);

        setContentView(R.layout.activity_main);

        TabsPagerAdapter adapter = new TabsPagerAdapter(getSupportFragmentManager());

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

        pager.setAdapter(adapter);

    }

}

PageFragment.java

package nc.example.com.pagertabstrip;

/**

 * Created by nc on 7/3/2017.

 */import android.support.v4.app.Fragment;

import android.os.Bundle;

import android.view.LayoutInflater;

import android.view.View;

import android.view.ViewGroup;

import android.widget.TextView;

public class PageFragment extends Fragment {

    private static final String ARG_PAGE_NUMBER = "page_number";

    public PageFragment() {

    }

    public static PageFragment newInstance(int page) {

        PageFragment fragment = new PageFragment();

        Bundle args = new Bundle();

        args.putInt(ARG_PAGE_NUMBER, page);

        fragment.setArguments(args);

        return fragment;

    }

    @Override

    public View onCreateView(LayoutInflater inflater, ViewGroup container,

                             Bundle savedInstanceState) {

        View rootView = inflater.inflate(R.layout.fragment_page_layout, container, false);

        TextView txt = (TextView) rootView.findViewById(R.id.page_number_label);

        int page = getArguments().getInt(ARG_PAGE_NUMBER, -1);

        txt.setText(String.format("Page %d", page));

        return rootView;

    }

}

TabsPagerAdapter.java

package nc.example.com.pagertabstrip;

/**

 * Created by nc on 7/3/2017.

 */import android.support.v4.app.Fragment;

import android.support.v4.app.FragmentManager;

import android.support.v4.app.FragmentPagerAdapter;

public class TabsPagerAdapter extends FragmentPagerAdapter {

    public TabsPagerAdapter(FragmentManager fm) {

        super(fm);

    }

    @Override

    public Fragment getItem(int position) {

        return PageFragment.newInstance(position + 1);

    }

    @Override

    public int getCount() {

        return 3;

    }

    @Override

    public CharSequence getPageTitle(int position) {

        return "TAB " + (position + 1);

    }