Android - Binary XML file line #19: Error inflating class fragment

Question

my android app started giving me this (logcat) error after start.

My Main Activity is:

import android.app.Activity;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.app.ActionBar;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentManager;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.ViewGroup;
import android.support.v4.widget.DrawerLayout;

public class MainActivity extends AppCompatActivity
        implements my.app.NavigationDrawerFragment.NavigationDrawerCallbacks {

    /**
     * Fragment managing the behaviors, interactions and presentation of the navigation drawer.
     */
    private my.app.NavigationDrawerFragment mNavigationDrawerFragment;

    /**
     * Used to store the last screen title. For use in {@link #restoreActionBar()}.
     */
    private CharSequence mTitle;

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

        mNavigationDrawerFragment = (my.app.NavigationDrawerFragment)
                getSupportFragmentManager().findFragmentById(R.id.navigation_drawer);
        mTitle = getTitle();

        // Set up the drawer.
        mNavigationDrawerFragment.setUp(
                R.id.navigation_drawer,
                (DrawerLayout) findViewById(R.id.drawer_layout));
    }

    @Override
    public void onNavigationDrawerItemSelected(int position) {

        Fragment myFragment = null;

        switch (position) {

            case 0:
                myFragment = new First_Fragment();
                break;

            case 1:
                myFragment = new Second_Fragment();
                break;

            case 2:
                myFragment = new Third_Fragment();
                break;

            case 3:
                myFragment = new Fourth_Fragment();
                break;
            //case 3:
            //    myFragment = new Caseopen_Fragment();
            //    break;
        }
        // update the main content by replacing fragments
        FragmentManager fragmentManager = getSupportFragmentManager();
        fragmentManager.beginTransaction()
                .replace(R.id.container, myFragment)
                .commit();
    }

    public void onSectionAttached(int number) {
        switch (number) {
            case 1:
                mTitle = getString(R.string.title_section1);
                break;
            case 2:
                mTitle = getString(R.string.title_section2);
                break;
            case 3:
                mTitle = getString(R.string.title_section3);
                break;
            case 4:
                mTitle = getString(R.string.title_section4);
                break;
            //case 4:
            //    mTitle = getString(R.string.title_caseopen);
            //    break;
        }
    }

    public void restoreActionBar() {
        ActionBar actionBar = getSupportActionBar();
        actionBar.setNavigationMode(ActionBar.NAVIGATION_MODE_STANDARD);
        actionBar.setDisplayShowTitleEnabled(true);
        actionBar.setTitle(mTitle);
    }


    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        if (!mNavigationDrawerFragment.isDrawerOpen()) {
            // Only show items in the action bar relevant to this screen
            // if the drawer is not showing. Otherwise, let the drawer
            // decide what to show in the action bar.
            getMenuInflater().inflate(R.menu.main, menu);
            restoreActionBar();
            return true;
        }
        return super.onCreateOptionsMenu(menu);
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        // Handle action bar item clicks here. The action bar will
        // automatically handle clicks on the Home/Up button, so long
        // as you specify a parent activity in AndroidManifest.xml.
        //int id = item.getItemId();

        //noinspection SimplifiableIfStatement
       // if (id == R.id.action_settings) {
       //     return true;
       // }

        return super.onOptionsItemSelected(item);
    }

    /**
     * A placeholder fragment containing a simple view.
     */
    public static class PlaceholderFragment extends Fragment {
        /**
         * The fragment argument representing the section number for this
         * fragment.
         */
        private static final String ARG_SECTION_NUMBER = "section_number";

        /**
         * Returns a new instance of this fragment for the given section
         * number.
         */
        public static PlaceholderFragment newInstance(int sectionNumber) {
            PlaceholderFragment fragment = new PlaceholderFragment();
            Bundle args = new Bundle();
            args.putInt(ARG_SECTION_NUMBER, sectionNumber);
            fragment.setArguments(args);
            return fragment;
        }

        public PlaceholderFragment() {
        }

        @Override
        public View onCreateView(LayoutInflater inflater, ViewGroup container,
                                 Bundle savedInstanceState) {
            View rootView = inflater.inflate(R.layout.fragment_main, container, false);
            return rootView;
        }

        @Override
        public void onAttach(Activity activity) {
            super.onAttach(activity);
            ((MainActivity) activity).onSectionAttached(
                    getArguments().getInt(ARG_SECTION_NUMBER));
        }
    }

}

Main Activity xml here

I googled a lot, only thing, that I found (use extend FragmentActivity) but then my restoreActionBar() does not work. Android studio does not show any errors, before I run the app.

Thank you.

Answer 1

From your comments, I have only one suggestion.

The Java fragment code in pixelsquad.csgohandbook.NavigationDrawerFragment is a suspect. For isolating the problem, can you try another fragment code?

You need to debug NavigationDrawerFragment when Activity is created, like with onCreate of that fragment. It's harder to debug if that fragment is not in the same project, as a warning.

From the logcat error, reading deeper into it, I think the class is not found. Error:

Caused by: java.lang.ClassNotFoundException: Didn't find class "pixelsquad.csgohandbook.NavigationDrawerFragment"

If that is so, then the class, JAR or APK file is simply not found in the system Java path.

Answer 2

I have fixed this problem. That I change property android:name to class. (although on Android Document, they say those properties are same, but it works !!!)

So, it should change from :

 android:name="pixelsquad.csgohandbook.NavigationDrawerFragment"

to

class="pixelsquad.csgohandbook.NavigationDrawerFragment"

So, new layout should be :

<FrameLayout android:id="@+id/container" android:layout_width="match_parent"
       android:layout_height="match_parent" />

    <!-- android:layout_gravity="start" tells DrawerLayout to treat
        this as a sliding drawer on the left side for left-to-right
        languages and on the right side for right-to-left languages.
        If you're not building against API 17 or higher, use
        android:layout_gravity="left" instead. -->
    <!-- The drawer is given a fixed width in dp and extends the full height of
        the container. -->
    <fragment android:id="@+id/navigation_drawer"
       android:layout_width="@dimen/navigation_drawer_width" android:layout_height="match_parent"
       android:layout_gravity="start"
       class ="pixelsquad.csgohandbook.NavigationDrawerFragment"
       tools:layout="@layout/fragment_navigation_drawer" />

Hope this help :)