Android Tablayout, почему вкладки не двигаются?

попробуйте этот код:

OneFragment.java

OneFragment.java
package info.androidhive.materialtabs.fragments;

import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;

import info.androidhive.materialtabs.R;


public class OneFragment extends Fragment{

public OneFragment() {
    // Required empty public constructor
}

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
}

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
                         Bundle savedInstanceState) {
    // Inflate the layout for this fragment
    return inflater.inflate(R.layout.fragment_one, container, false);
}

 }

fragment_one.xml

 fragment_one.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"
 tools:context = "info.androidhive.materialtabs.fragments.OneFragment">

 <TextView
    android:layout_width = "wrap_content"
    android:layout_height = "wrap_content"
    android:text = "@string/one"
    android:textSize = "40dp"
    android:textStyle = "bold"
    android:layout_centerInParent = "true"/>

</RelativeLayout>

activity_main.xml

<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.v7.widget.Toolbar
        android:id = "@+id/toolbar"
        android:layout_width = "match_parent"
        android:layout_height = "?attr/actionBarSize"
        android:background = "?attr/colorPrimary"
        app:layout_scrollFlags = "scroll|enterAlways"
        app:popupTheme = "@style/ThemeOverlay.AppCompat.Light" />

    <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>

MainActivity.java

  package info.androidhive.materialtabs.activity;

import android.os.Bundle;
import android.support.design.widget.TabLayout;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentManager;
import android.support.v4.app.FragmentPagerAdapter;
import android.support.v4.view.ViewPager;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.Toolbar;

import java.util.ArrayList;
import java.util.List;

import info.androidhive.materialtabs.R;
import info.androidhive.materialtabs.fragments.OneFragment;
import info.androidhive.materialtabs.fragments.ThreeFragment;
import info.androidhive.materialtabs.fragments.TwoFragment;

[![][1]][1]public class MainActivity extends AppCompatActivity {

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

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

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

    getSupportActionBar().setDisplayHomeAsUpEnabled(true);

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

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

private void setupViewPager(ViewPager viewPager) {
    ViewPagerAdapter adapter = new 
ViewPagerAdapter(getSupportFragmentManager());
    adapter.addFragment(new OneFragment(), "ONE");
    adapter.addFragment(new TwoFragment(), "TWO");
    adapter.addFragment(new ThreeFragment(), "THREE");
    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);
    }
  }
 }

и добавляем основное действие, вызывающее 3 вкладки

     private class MyPagerAdapter extends FragmentPagerAdapter {

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

    @Override
    public Fragment getItem(int pos) {
        switch(pos) {
            case 0: return SimpleFragment.newInstance("FirstFragment, Instance 1");
            case 1: return PieView.newInstance("SecondFragment, Instance 1");
            case 2: return PieView1.newInstance("ThirdFragment, Instance 1");
             case 3: return DataSaveDetails.newInstance("ThirdFragment, Instance 1");
              default:
        }
        return null;
    }

это работает, попробуйте это

В вашем методе getItem (). Используйте Switch и возвращайте их фрагменты вместо добавления всех фрагментов в метод addFragment.

    public Fragment getItem(int position){
     switch(position){
       case 0 : return new Tab1Fragment();
       case 1 : return new Tab2Fragment();
       case 2 : return new Tab3Fragment();
     }

    }

используйте этот XML, как указано в библиотеке, за которой вы следовали, а затем любой дизайн, который вы хотите добавить в макеты фрагментов, которые вы приняли. все будет работать нормально

<?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"
    xmlns:tools = "http://schemas.android.com/tools"
    android:layout_width = "match_parent"
    android:layout_height = "match_parent"
    android:orientation = "vertical"
    tools:context = "com.example.chirag.slidingtabsusingviewpager.MainActivity">

    <android.support.v7.widget.Toolbar
        android:layout_width = "match_parent"
        android:layout_height = "wrap_content"
        android:id = "@+id/toolbar"
        android:background = "@color/colorPrimary"
        android:minHeight = "?attr/actionBarSize"
        android:theme = "@style/ThemeOverlay.AppCompat.Dark.ActionBar"
        app:popupTheme = "@style/ThemeOverlay.AppCompat.Light">

        <TextView
            android:layout_width = "wrap_content"
            android:layout_height = "wrap_content"
            android:text = "SlidingTabsUsingViewPager"
            android:textSize = "20dp"/>


    </android.support.v7.widget.Toolbar>

    <android.support.design.widget.TabLayout
        android:layout_width = "match_parent"
        android:layout_height = "wrap_content"
        android:id = "@+id/tablayout"
        android:background = "@color/colorPrimary"
        android:minHeight = "?attr/actionBarSize"
        android:theme = "@style/ThemeOverlay.AppCompat.Dark.ActionBar">

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

    <android.support.v4.view.ViewPager
        android:layout_width = "match_parent"
        android:layout_height = "fill_parent"
        android:id = "@+id/pager">

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

</LinearLayout>