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What is ViewPager?
What is ViewPager?
1 Answer
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ViewPager in Android:
ViewPager is a class and UI widgets in android that allow the user to swipe the page left to right or right to left to see an entirely new screen. ViewPager provide a facility to dynamically add and remove pages at any time on your project. It is very useful for showing multiple tabs on your android screen. If you have using ViewPager then you have to keep the knowledge of Fragment and PagerAdapters and TabLayout.
Here, we are implementing a ViewPager Example using View and Adapter classes.
Android ViewPager File Structure Example
Android ViewPager Example:
activity_main.java
<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout 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"
tools:context="com.example.msclient009.tablayoutexample.MainActivity">
<android.support.design.widget.TabLayout
android:id="@+id/tabLayout"
android:layout_width="match_parent"
android:layout_height="wrap_content"
app:tabTextColor="#fff"
android:background="#1db995">
</android.support.design.widget.TabLayout>
<android.support.v4.view.ViewPager
android:id="@+id/viewPager"
android:layout_width="355dp"
android:layout_height="455dp"
app:layout_constraintTop_toBottomOf="@+id/tabLayout"
tools:layout_editor_absoluteY="8dp">
</android.support.v4.view.ViewPager>
</android.support.constraint.ConstraintLayout>
ActivityMain.java
package com.example.msclient009.tablayoutexample;
import android.support.design.widget.TabLayout;
import android.support.v4.view.ViewPager;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
public class MainActivity extends AppCompatActivity {
TabLayout tabLayout;
ViewPager viewPager;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
tabLayout=(TabLayout)findViewById(R.id.tabLayout);
viewPager=(ViewPager)findViewById(R.id.viewPager);
tabLayout.addTab(tabLayout.newTab().setText("Home"));
tabLayout.addTab(tabLayout.newTab().setText("About"));
tabLayout.addTab(tabLayout.newTab().setText("Contact"));
tabLayout.setTabGravity(TabLayout.GRAVITY_FILL);
final MyAdapter adapter = new MyAdapter(this,getSupportFragmentManager(), tabLayout.getTabCount());
viewPager.setAdapter(adapter);
viewPager.addOnPageChangeListener(new TabLayout.TabLayoutOnPageChangeListener(tabLayout));
tabLayout.addOnTabSelectedListener(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) {
}
});
}
}
MyAdapter.java
package com.example.msclient009.tablayoutexample;
import android.content.Context;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentPagerAdapter;
import android.support.v4.app.FragmentManager;
public class MyAdapter extends FragmentPagerAdapter {
private Context myContext;
int totalTabs;
public MyAdapter(Context context, FragmentManager fm, int totalTabs) {
super(fm);
myContext = context;
this.totalTabs = totalTabs;
}
// this is for fragment tabs
@Override
public Fragment getItem(int position) {
switch (position) {
case 0:
HomeFragment homeFragment = new HomeFragment();
return homeFragment;
case 1:
AboutFragment aboutFragment = new AboutFragment();
return aboutFragment;
case 2:
ContactFragment contactFragment = new ContactFragment();
return contactFragment;
default:
return null;
}
}
// this counts total number of tabs
@Override
public int getCount() {
return totalTabs;
}
}
home_fragment.xml
<?xml version="1.0" encoding="utf-8"?>
<FrameLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:id="@+id/homeFragment"
android:layout_height="match_parent">
<TextView
android:layout_width="match_parent"
android:layout_height="match_parent"
android:gravity="center"
android:textColor="#037103"
android:textSize="30dp"
android:textStyle="bold"
android:text="@string/home_fragment" />
</FrameLayout>
HomeFragment.java
package com.example.msclient009.tablayoutexample;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
public class HomeFragment extends Fragment {
public HomeFragment() {
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
// Inflate the layout for this fragment
View mView = inflater.inflate(R.layout.home_fragment,container, false);
return mView;
}
}
about_fragment.xml
<?xml version="1.0" encoding="utf-8"?>
<FrameLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:id="@+id/aboutFragment"
android:layout_height="match_parent">
<TextView
android:layout_width="match_parent"
android:layout_height="match_parent"
android:gravity="center"
android:textColor="#037103"
android:textSize="30dp"
android:textStyle="bold"
android:text="@string/about_fragment"/>
</FrameLayout>
AboutFragment.java
package com.example.msclient009.tablayoutexample;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
public class AboutFragment extends Fragment {
public AboutFragment() {
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
// Inflate the layout for this fragment
View mView = inflater.inflate(R.layout.about_fragment,container, false);
return mView;
}
}
contact_fragment.xml
<?xml version="1.0" encoding="utf-8"?>
<FrameLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:id="@+id/contactFragment"
android:layout_height="match_parent">
<TextView
android:layout_width="match_parent"
android:layout_height="match_parent"
android:gravity="center"
android:textColor="#037103"
android:textSize="30dp"
android:textStyle="bold"
android:text="@string/contact_fragment"/>
</FrameLayout>
ContactFragment.java
package com.example.msclient009.tablayoutexample;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
public class ContactFragment extends Fragment {
public ContactFragment() {
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
// Inflate the layout for this fragment
View mView = inflater.inflate(R.layout.contact_fragment,container, false);
return mView;
}
}
string.xml
<resources>
<string name="app_name">TabLayoutExample</string>
<string name="home_fragment">Home Fragment</string>
<string name="about_fragment">About Fragment</string>
<string name="contact_fragment">Contact Fragment</string>
</resources>
Output:
