See this simple complete example:
Here I used TabLayout also which is often used with ViewPager, so will be useful for you on next.
It requires API:
compile 'com.android.support:design:25.3.1'
You can ignore and remove all parts of TabLayout from xml and java files if want to go simpler at this instance.
1. activity_main.xml
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout 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.v4.view.ViewPager
android:layout_width="match_parent"
android:layout_height="match_parent"
android:id="@+id/viewPager"/>
<android.support.design.widget.TabLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:background="@color/colorPrimary"
app:tabIndicatorColor="@color/colorPrimaryDark"
app:layout_scrollFlags="scroll|enterAlways"
android:id="@+id/tabLayout"/>
</RelativeLayout>
2. Fragment Tab1.xml
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent" android:layout_height="match_parent">
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_centerHorizontal="true"
android:layout_centerVertical="true"
android:text="TAB 1"
android:id="@+id/textTab1"/>
</RelativeLayout>
3. Fragment Tab2.xml
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent" android:layout_height="match_parent">
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_centerHorizontal="true"
android:layout_centerVertical="true"
android:text="TAB 2"
android:id="@+id/textTab2"/>
</RelativeLayout>
4. Fragment Tab3.xml
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent" android:layout_height="match_parent">
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_centerHorizontal="true"
android:layout_centerVertical="true"
android:text="TAB 3"
android:id="@+id/textSpacerNoTitleab3"/>
</RelativeLayout>
5. MainActivity.java
public class MainActivity extends AppCompatActivity
implements TabLayout.OnTabSelectedListener, ViewPager.OnPageChangeListener{
ViewPager viewPager;
TabLayout tabLayout;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
viewPager = (ViewPager) findViewById(R.id.viewPager);
tabLayout = (TabLayout) findViewById(R.id.tabLayout);
tabLayout.addTab(tabLayout.newTab().setText("Page 1"));
tabLayout.addTab(tabLayout.newTab().setText("Page 2"));
tabLayout.addTab(tabLayout.newTab().setText("Page 3"));
tabLayout.setTabGravity(TabLayout.GRAVITY_FILL);
tabLayout.addOnTabSelectedListener(this);
viewPager.setAdapter(new VPAdapter(getSupportFragmentManager()));
viewPager.addOnPageChangeListener(this);
}
@Override
public void onTabSelected(TabLayout.Tab tab) {
w("onTabSelected(): "+tab.getPosition());
viewPager.setCurrentItem(tab.getPosition());
}
@Override
public void onTabUnselected(TabLayout.Tab tab) {
}
@Override
public void onTabReselected(TabLayout.Tab tab) {
}
@Override
public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {
}
@Override
public void onPageSelected(int position) {
w("onPageSelected(): "+position);
TabLayout.Tab tab = tabLayout.getTabAt(position);
if(tab!=null)tab.select();
}
@Override
public void onPageScrollStateChanged(int state) {
}
void w(String string){
Log.w("MKN",getClass().getSimpleName()+" "+string);
}
}
6. Fragment class Tab1.java
public class Tab1 extends Fragment {
@Nullable
@Override
public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
super.onCreateView(inflater, container, savedInstanceState);
return inflater.inflate(R.layout.tab1,container,false);
}
}
7. Fragment class Tab2.java
public class Tab2 extends Fragment {
@Nullable
@Override
public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
super.onCreateView(inflater, container, savedInstanceState);
return inflater.inflate(R.layout.tab2,container,false);
}
}
8. Fragment class Tab3.java
public class Tab3 extends Fragment {
@Nullable
@Override
public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
super.onCreateView(inflater, container, savedInstanceState);
return inflater.inflate(R.layout.tab3,container,false);
}
}
9. Adapter class VPAdapter.java
public class VPAdapter extends FragmentPagerAdapter {
public VPAdapter(FragmentManager fm) {
super(fm);
}
@Override
public Fragment getItem(int position) {
if(position == 0) return new Tab1();
if(position == 1) return new Tab2();
if(position == 2) return new Tab3();
throw new IllegalStateException("Unexpected position " + position);
}
@Override
public int getCount() {
return 3;
}
}