ViewPager doesn't swipe with FragmentPagerAdapter

Question

I have two fragments in an Activity, In portrait mode the first one (ListFragment) is shown when user clicks in somewhere in ListView the second one is shown, while in landscape mode both the fragments are shown. However I want to use the swipe feature while in the portrait mode and that should show the next fragment like this example,

This is my main laucher Activity which extends FragmentActivity,

package com.myexample.fragmentdemoexample;

import java.util.LinkedList;
import java.util.List;
import java.util.Vector;

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.app.ListFragment;
import android.support.v4.view.ViewPager;
import android.util.Log;
import android.view.ViewGroup;

public class MainFragmentActivity extends FragmentActivity {
    private static int NUM_ITEMS = 4;

    MyAdapter mAdapter;

    ViewPager mPager;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        mPager = (ViewPager) findViewById(R.id.pager);
        instantiateFragments();
        Log.i("MainFragmentActivity", "MainFragmentActivity is Created");
    }

    public void instantiateFragments() {
        List<Fragment> fragments = new Vector<Fragment>();
        fragments.add(Fragment.instantiate(this, MyListFragment.class.getName()));
        fragments.add(Fragment.instantiate(this, DetailFragment.class.getName()));
        mAdapter = new MyAdapter(getSupportFragmentManager(), fragments);
        mPager.setAdapter(mAdapter);
        mPager.setCurrentItem(0);
    }

    public class MyAdapter extends FragmentPagerAdapter {
        private FragmentManager frmanager;
        private List<Fragment> fragments;

        public MyAdapter(FragmentManager fm, List<Fragment> fragList) {
            super(fm);
            frmanager = fm;
            fragments = fragList;
        }

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

        @Override
        public Fragment getItem(int position) {
            return fragments.get(position);
        }
    }
}

This is my layout/main.xml file

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="horizontal" >

    <android.support.v4.view.ViewPager
        xmlns:android="http://schemas.android.com/apk/res/android"
        android:id="@+id/pager"
        android:layout_width="match_parent"
        android:layout_height="0px"
        android:layout_weight="1" >
    </android.support.v4.view.ViewPager>

    <fragment
        android:id="@+id/listFragment"
        android:layout_width="150dip"
        android:layout_height="match_parent"
        class="com.myexample.fragmentdemoexample.MyListFragment"
        android:tag="listFragment" >
    </fragment>

    <fragment
        android:id="@+id/detailFragment"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        class="com.myexample.fragmentdemoexample.DetailFragment"
        android:tag="detailFragment" >
        <!-- Preview: layout=@layout/details -->
    </fragment>

</LinearLayout>

and /layout-port/main.xml file contains

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:orientation="horizontal" >

    <android.support.v4.view.ViewPager
        android:id="@+id/pager"
        android:layout_width="match_parent"
        android:layout_height="0px"
        android:layout_weight="1" >
    </android.support.v4.view.ViewPager>

    <fragment
        android:id="@+id/listFragment"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        class="com.myexample.fragmentdemoexample.MyListFragment" />

</LinearLayout>

I don't know why View Pager is not swiping in to next fragment... How can I do that ? I am using Fragment API for the first time.. so please give some pointers to right direction.

NOTE For other files see this question

score 3 · Accepted Answer · answered Aug 02 '12 at 06:07

Finally after hours of harrasment the problem was solved by removing the Fragment tags from the main layout file. Now main.xml contains

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="horizontal" >

    <android.support.v4.view.ViewPager
        xmlns:android="http://schemas.android.com/apk/res/android"
        android:id="@+id/pager"
        android:layout_width="match_parent"
        android:layout_height="0px"
        android:layout_weight="1" >
    </android.support.v4.view.ViewPager>


</LinearLayout>

This might be helpful for others with similar problem...

score 2 · Answer 2 · answered May 04 '16 at 15:56

Even though it doesn't answer the question directly, but it has answer on similar problem I have faced. may be it will help others having similar problem.

If you are having a layout like

<AppBarLayout>
    <ToolBar />
        <TabLayout />
            <ViewPager />
</AppBarLayout>

The mistake here is ViewPager should not be inside AppBarLayout. So change your code to:

<AppBarLayout>
    <ToolBar />
        <TabLayout />
</AppBarLayout>
<ViewPager />

ViewPager doesn't swipe with FragmentPagerAdapter

2 Answers2