Haxor Haxor - 18 days ago 5
Android Question

How to implement a ViewPager with different Fragments / Layouts

When I start an activity which implements viewpager, the viewpager created various fragments. I want to use different layouts for each fragment, but the problem is that viewpager shows only two layouts at the max (second layout on all of the remaining fragments after 1).

Here is the code for SwipeActivity which implements the viewpager :

public class SwipeActivity extends FragmentActivity
{

MyPageAdapter pageAdapter;

@Override
protected void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_swipe);
pageAdapter = new MyPageAdapter(getSupportFragmentManager());
ViewPager pager=(ViewPager)findViewById(R.id.pager);
pager.setAdapter(pageAdapter);
ActionBar bar = getActionBar();
bar.setDisplayHomeAsUpEnabled(true);
}
/**
* Custom Page adapter
*/
private class MyPageAdapter extends FragmentPagerAdapter
{
public MyPageAdapter(FragmentManager fm)
{
super(fm);
}
@Override
public int getCount()
{
return 5;
}
@Override
public Fragment getItem(int position)
{
switch(position)
{
case 0: return new MyFragment();
case 1: return SecondFragment.newInstance("asdasd");
default : return RamFragment.newInstance("s");
}
}
}
}


Here is the code for the fragments

public class MyFragment extends Fragment
{
@Override
public View onCreateView(LayoutInflater paramLayoutInflater, ViewGroup paramViewGroup, Bundle paramBundle)
{
return paramLayoutInflater.inflate(R.layout.processorlayout, paramViewGroup, false);
}
}


I used 5 fragments like this, all having different layouts, but the viewpager shows only 2 at the max.

EDIT : code for SecondFragment

public class SecondFragment extends Fragment
{
public static final String EXTRA_MESSAGE = "EXTRA_MESSAGE";

public static final SecondFragment newInstance(String paramString)
{
SecondFragment f = new SecondFragment();
Bundle localBundle = new Bundle(1);
localBundle.putString("EXTRA_MESSAGE", paramString);
f.setArguments(localBundle);
return f;
}

@Override
public View onCreateView(LayoutInflater paramLayoutInflater, ViewGroup paramViewGroup, Bundle paramBundle)
{
return paramLayoutInflater.inflate(R.layout.motherboardlayout, paramViewGroup, false);
}


}

Answer

As this is a very frequently asked question, I wanted to take the time and effort to explain the ViewPager with multiple Fragments and Layouts in detail. Here you go.

ViewPager with multiple Fragments and Layout files - How To

The following is a complete example of how to implement a ViewPager with different fragment Types and different layout files.

In this case, I have 3 Fragment classes, and a different layout file for each class. In order to keep things simple, the fragment-layouts only differ in their background color. Of course, any layout-file can be used for the Fragments.

FirstFragment.java has a orange background layout, SecondFragment.java has a green background layout and ThirdFragment.java has a red background layout. Furthermore, each Fragment displays a different text, depending on which class it is from and which instance it is.

Also be aware that I am using the support-library's Fragment: android.support.v4.app.Fragment

MainActivity.java (Initializes the Viewpager and has the adapter for it as an inner class). Again have a look at the imports. I am using the android.support.v4 package.

import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentActivity;
import android.support.v4.app.FragmentManager;
import android.support.v4.app.FragmentPagerAdapter;
import android.support.v4.view.ViewPager;

public class MainActivity extends FragmentActivity {

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

        ViewPager pager = (ViewPager) findViewById(R.id.viewPager);
        pager.setAdapter(new MyPagerAdapter(getSupportFragmentManager()));
    }

    private class MyPagerAdapter extends FragmentPagerAdapter {

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

        @Override
        public Fragment getItem(int pos) {
            switch(pos) {

            case 0: return FirstFragment.newInstance("FirstFragment, Instance 1");
            case 1: return SecondFragment.newInstance("SecondFragment, Instance 1");
            case 2: return ThirdFragment.newInstance("ThirdFragment, Instance 1");
            case 3: return ThirdFragment.newInstance("ThirdFragment, Instance 2");
            case 4: return ThirdFragment.newInstance("ThirdFragment, Instance 3");
            default: return ThirdFragment.newInstance("ThirdFragment, Default");
            }
        }

        @Override
        public int getCount() {
            return 5;
        }       
    }
}

activity_main.xml (The MainActivitys .xml file) - a simple layout file, only containing the ViewPager that fills the whole screen.

<android.support.v4.view.ViewPager
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:id="@+id/viewPager"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    />

The Fragment classes, FirstFragment.java import android.support.v4.app.Fragment;

public class FirstFragment extends Fragment {

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
        View v = inflater.inflate(R.layout.first_frag, container, false);

        TextView tv = (TextView) v.findViewById(R.id.tvFragFirst);
        tv.setText(getArguments().getString("msg"));

        return v;
    }

    public static FirstFragment newInstance(String text) {

        FirstFragment f = new FirstFragment();
        Bundle b = new Bundle();
        b.putString("msg", text);

        f.setArguments(b);

        return f;
    }
}

first_frag.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"
    android:background="@android:color/holo_orange_dark" >

    <TextView
        android:id="@+id/tvFragFirst"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_centerHorizontal="true"
        android:layout_centerVertical="true"
        android:textSize="26dp"
        android:text="TextView" />
</RelativeLayout>

SecondFragment.java

public class SecondFragment extends Fragment {

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
    View v = inflater.inflate(R.layout.second_frag, container, false);

    TextView tv = (TextView) v.findViewById(R.id.tvFragSecond);
    tv.setText(getArguments().getString("msg"));

    return v;
}

public static SecondFragment newInstance(String text) {

    SecondFragment f = new SecondFragment();
    Bundle b = new Bundle();
    b.putString("msg", text);

    f.setArguments(b);

    return f;
}
}

second_frag.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"
    android:background="@android:color/holo_green_dark" >

    <TextView
        android:id="@+id/tvFragSecond"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_centerHorizontal="true"
        android:layout_centerVertical="true"
        android:textSize="26dp"
        android:text="TextView" />

</RelativeLayout>

ThirdFragment.java

public class ThirdFragment extends Fragment {

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
    View v = inflater.inflate(R.layout.third_frag, container, false);

    TextView tv = (TextView) v.findViewById(R.id.tvFragThird);      
    tv.setText(getArguments().getString("msg"));

    return v;
}

public static ThirdFragment newInstance(String text) {

    ThirdFragment f = new ThirdFragment();
    Bundle b = new Bundle();
    b.putString("msg", text);

    f.setArguments(b);

    return f;
}
}

third_frag.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"
    android:background="@android:color/holo_red_light" >

    <TextView
        android:id="@+id/tvFragThird"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_centerHorizontal="true"
        android:layout_centerVertical="true"
        android:textSize="26dp"
        android:text="TextView" />

</RelativeLayout>

The end result is the following:

The Viewpager holds 5 Fragments, Fragments 1 is of type FirstFragment, and displays the first_frag.xml layout, Fragment 2 is of type SecondFragment and displays the second_frag.xml, and Fragment 3-5 are of type ThirdFragment and all display the third_frag.xml.

enter image description here

Above you can see the 5 Fragments between which can be switched via swipe to the left or right. Only one Fragment can be displayed at the same time of course.

Last but not least:

I would recommend that you use an empty constructor in each of your Fragment classes.

Instead of handing over potential parameters via constructor, use the newInstance(...) method and the Bundle for handing over parameters.

This way if detached and re-attached the object state can be stored through the arguments. Much like Bundles attached to Intents.

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