Fragment activity with FragmentView crash when navigating backward

Question

In this example I can navigate between 3 pages by swipe. The first page (page0.xml) contains a fragment (@+id/fragment1). Works fine when swiping forward, but the problem is when navigating back from page2 to page1, the application crash.

Here is stacktrace

FATAL EXCEPTION: main
android.view.InflateException: Binary XML file line #14 Error inflating class fragment

How to solve this?

package crash;
import com.example.crash.R;
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;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;  

  public class Main extends FragmentActivity{

@Override
protected void onCreate(Bundle arg0) {
    // TODO Auto-generated method stub
    setContentView(R.layout.main);
    FragmentManager fm = getSupportFragmentManager();
    ViewPager vp = (ViewPager) findViewById(R.id.my_viewpager);
    MyAdapter ad = new MyAdapter(fm);
    vp.setAdapter(ad);

    super.onCreate(arg0);
}

public static class MyAdapter extends FragmentPagerAdapter {

    public MyAdapter(FragmentManager fm) {

        super(fm);
        // TODO Auto-generated constructor stub
        // this.myContext=myContext;
    }

    @Override
    public Fragment getItem(int arg0) {
        // TODO Auto-generated method stub
        Bundle bu = new Bundle();
        bu.putInt("page", arg0);
        Fragment myFragment = new MyFragment();
        myFragment.setArguments(bu);
        return myFragment;

    }

    @Override
    public int getCount() {
        // TODO Auto-generated method stub
        return 3;
    }
}

public static class MyFragment extends Fragment {

    @Override
    public void onCreate(Bundle savedInstanceState) {
        // TODO Auto-generated method stub
        super.onCreate(savedInstanceState);
    }

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
            Bundle savedInstanceState) {

        // TODO Auto-generated method stub
        View v;
        Bundle bu = getArguments();
        switch (bu.getInt("page")) {
        case 0:
            return inflater.inflate(R.layout.page0, container, false);
        case 1:
            return inflater.inflate(R.layout.page1, container, false);
        case 2:
            return inflater.inflate(R.layout.page2, container, false);
        default:
            return null;
        }

    }

    public static class MyIncludedFragment extends Fragment{
        @Override
        public View onCreateView(LayoutInflater inflater, ViewGroup container,
                Bundle savedInstanceState) {
            // TODO Auto-generated method stub

            return inflater.inflate(R.layout.fragment,container,false);

        }
    }
}

}

main.xml

<?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="vertical" >
 <android.support.v4.view.ViewPager
        xmlns:android="http://schemas.android.com/apk/res/android"
        android:layout_width="match_parent"
        android:layout_height="match_parent" 
        android:id="@+id/my_viewpager"
        >
 </android.support.v4.view.ViewPager>   

</LinearLayout>

page0.xml

   <?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="vertical" >

<TextView
    android:id="@+id/textView1"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="Page 0"
    android:textSize="48dp" />

<fragment
    android:id="@+id/fragment1"
    android:name="crash.Main$MyFragment$MyIncludedFragment"
    android:layout_width="match_parent"
    android:layout_height="wrap_content" />

</LinearLayout>

page1.xml

<?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="vertical" >

    <TextView
        android:id="@+id/textView1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Page 1"
        android:textSize="48dp" />

</LinearLayout>

page2.xml

<?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="vertical" >

    <TextView
        android:id="@+id/textView1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Page 2"
        android:textSize="48dp" />

</LinearLayout>

fragment.xml

<?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:background="#0ff"
    android:orientation="vertical" >

    <TextView
        android:id="@+id/textView1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="My fragment"
        android:textSize="48dp" />

</LinearLayout>

score 1 · Answer 1 · edited May 23 '17 at 12:14

1

Replace your MyAdapter with this:

public class FragmentAdapter extends FragmentStatePagerAdapter {

    private final List<Fragment> mFragments = new ArrayList<>();
    private final List<String> mFragmentTitles = new ArrayList<>();

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

    public void addFragment(Fragment fragment, String title) {
        mFragments.add(fragment);
        mFragmentTitles.add(title);
    }

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

    @Override
    public int getCount() {
        return mFragments.size();
    }

    @Override
    public CharSequence getPageTitle(int position) {
        return mFragmentTitles.get(position);
    }
}

Also, it is always a good idea to use newInstance() instead of invoking the default constructor. See this SO link: Best practice for instantiating a new Android Fragment

That being done, set the adapter to the viewpager using something like this:

FragmentAdapter fragmentAdapter = new FragmentAdapter(getSupportFragmentManager());
fragmentAdapter.addFragment(MyFragment.newInstance(0), "Title 1");
fragmentAdapter.addFragment(MyFragment.newInstance(1), "Title 2");
fragmentAdapter.addFragment(MyFragment.newInstance(2), "Title 3");
viewPager.setAdapter(mFragmentAdapter);

Edit: To define the newInstance() method in your case, you need to do something like this:

public static class MyFragment extends Fragment {
    public static MyFragment newInstance(int arg0) {
         Bundle bu = new Bundle();
         bu.putInt("page", arg0);
         Fragment myFragment = new MyFragment();
         myFragment.setArguments(bu);
         return myFragment;
    }
    // rest of your code remains the same
}

edited May 23 '17 at 12:14

Community

1
1

answered Sep 24 '15 at 13:28

Abhishek Dabholkar

11
4

The method newInstance() is undefined for the type Main.MyFragment – Domonkos Bart Sep 24 '15 at 14:22
You need to implement that method yourself. However, I've updated my answer with an example of how you need to implement it. – Abhishek Dabholkar Sep 24 '15 at 14:32
Unfortunately Crash has stopped (when swiping back to first page) – Domonkos Bart Sep 24 '15 at 15:31
I made a mistake while typing. You need to pass your argument as newInstance(int arg0). Check the updated answer. – Abhishek Dabholkar Sep 24 '15 at 16:10
Is there any new error you seem to be getting or is your problem solved now? – Abhishek Dabholkar Sep 24 '15 at 16:12
I already did. `MyNewFragment.newInstance(0)` 1 and 2. If only 0 and 1, there is no error. If 0 1 and 2 then when moving from 2 to 1 program stops. – Domonkos Bart Sep 24 '15 at 16:47
could you set `super.onCreate(args0)` as the first line before `setContentView`. Not really sure if that could create bugs. – Abhishek Dabholkar Sep 24 '15 at 17:15
09-24 19:22:15.406: E/AndroidRuntime(7568): FATAL EXCEPTION: main 09-24 19:22:15.406: E/AndroidRuntime(7568): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.crash/crash.Main}: java.lang.IllegalStateException: Already attached – Domonkos Bart Sep 24 '15 at 17:25
Sorry I forgot to clear `super.onCreate()` from the last line. But same error. – Domonkos Bart Sep 24 '15 at 17:29
I see that you are using nested fragments inside a viewpager. In that case it's always a good option to call getChildFragmentManager() instead of getSupportFragmentManager() – Abhishek Dabholkar Sep 25 '15 at 02:07
The method getChildFragmentManager() is undefined for the type Main – Domonkos Bart Sep 25 '15 at 02:34

Fragment activity with FragmentView crash when navigating backward

1 Answers1