搜索过滤器始终返回列表视图项的0位置

Question

我有使用Arraydopter的自定义列表视图。我实现了搜索过滤器，但问题是在列表视图中搜索项目后，它始终在列表视图中返回0位置项目。没有searchfilter，它可以正常工作。请帮助我如何解决此问题。这是我的代码：

我的主要活动

package bible.swordof.God;

import android.content.Intent;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.os.Bundle;
import android.speech.RecognizerIntent;
import android.support.design.widget.NavigationView;
import android.support.v4.app.Fragment;
import android.support.v4.view.GravityCompat;
import android.support.v4.view.MenuItemCompat;
import android.support.v4.widget.DrawerLayout;
import android.support.v7.app.ActionBarDrawerToggle;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.SearchView;
import android.support.v7.widget.Toolbar;
import android.text.TextUtils;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ListView;
import android.widget.Toast;

import java.util.ArrayList;
import java.util.Locale;

public class MainActivity extends AppCompatActivity implements NavigationView.OnNavigationItemSelectedListener {
    private ListView listView;
    private ArrayList<String> books;
    private ListViewAdapter adapter;
    private DatabaseHelper mDBHelper=null;
    private SQLiteDatabase mDb=null;

//life is awesome

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        Toolbar toolbar=(Toolbar) findViewById(R.id.toolbar);
        setSupportActionBar(toolbar);

        DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
        ActionBarDrawerToggle toggle = new ActionBarDrawerToggle(
                this, drawer, toolbar, R.string.navigation_drawer_open, R.string.navigation_drawer_close);
        drawer.addDrawerListener(toggle);
        toggle.syncState();

        NavigationView navigationView = (NavigationView) findViewById(R.id.nav_view);
        navigationView.setNavigationItemSelectedListener(this);

        setData();
        listView =findViewById(R.id.list);
        adapter = new ListViewAdapter(MainActivity.this, R.layout.item_listview, books);
        listView.setAdapter(adapter);

        listView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
            @Override
            public void onItemClick(AdapterView<?> parent, View view, int position, long id) {

                 int booknumber=position;
                 String  bookname=books.get(position);




                Toast.makeText(MainActivity.this, ""+booknumber, Toast.LENGTH_SHORT).show();

             /*   Intent intent=new Intent(MainActivity.this,Chapters.class);
                intent.putExtra("booknumber",booknumber);

                intent.putExtra("bookname",bookname);

                startActivity(intent);*/



            }
        });
    }



    @Override
    public void onBackPressed() {
        DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
        if (drawer.isDrawerOpen(GravityCompat.START)) {
            drawer.closeDrawer(GravityCompat.START);
        } else {
            super.onBackPressed();
        }
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {

        switch (item.getItemId()){
            case R.id.search_voice_btn:
                Intent intent = new Intent(RecognizerIntent.ACTION_RECOGNIZE_SPEECH);
                intent.putExtra(RecognizerIntent.EXTRA_LANGUAGE_MODEL, RecognizerIntent.LANGUAGE_MODEL_FREE_FORM);
                intent.putExtra(RecognizerIntent.EXTRA_LANGUAGE, Locale.getDefault());
                if (intent.resolveActivity(getPackageManager()) != null) {
                    startActivityForResult(intent, 10);
                } else {
                    Toast.makeText(this, "Your Device Don't Support Speech Input", Toast.LENGTH_SHORT).show();
                }




                break;
        }
        return super.onOptionsItemSelected(item);
    }
    @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        super.onActivityResult(requestCode, resultCode, data);

        switch (requestCode) {
            case 10:
                if (resultCode == RESULT_OK && data != null) {

                    ArrayList<String> result = data.getStringArrayListExtra(RecognizerIntent.EXTRA_RESULTS);



                    Toast.makeText(this, ""+result.get(0), Toast.LENGTH_SHORT).show();



                }
                break;
        }
    }

    @Override
    public boolean onCreateOptionsMenu( Menu menu) {
        getMenuInflater().inflate(R.menu.main, menu);

        MenuItem myActionMenuItem = menu.findItem(R.id.action_search);
        final SearchView searchView = (SearchView) MenuItemCompat.getActionView(myActionMenuItem);
        searchView.setOnQueryTextListener(new SearchView.OnQueryTextListener() {
            @Override
            public boolean onQueryTextSubmit(String query) {
                return false;
            }

            @Override
            public boolean onQueryTextChange(String newText) {
                if (TextUtils.isEmpty(newText)) {
                    adapter.filter("");
                    listView.clearTextFilter();

                } else {
                    adapter.filter(newText);

                }
                return true;
            }
        });

        return true;
    }
    @SuppressWarnings("StatementWithEmptyBody")
    @Override
    public boolean onNavigationItemSelected(MenuItem item) {
        // Handle navigation view item clicks here.
        Fragment fragment;
        int id = item.getItemId();


        if (id == R.id.home) {

            Intent intent=new Intent(this,MainActivity.class);
            startActivity(intent);

        } else if (id == R.id.favoruite)
        {
         Intent intent=new Intent(this,Favourite.class);

         startActivity(intent);
        }  else if (id == R.id.nav_manage) {

        } else if (id == R.id.nav_share) {

        } else if (id == R.id.nav_send) {

        }

        DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
        drawer.closeDrawer(GravityCompat.START);
        return true;
    }

    private void setData() {


      books= new ArrayList<>();

        mDBHelper = new DatabaseHelper(this);
        mDb = mDBHelper.getReadableDatabase();

        Cursor cursor = mDb.rawQuery("select * from key_english", new String[]{});


        if(cursor!=null && cursor.getCount() > 0)
        {
            if (cursor.moveToFirst())
            {
                do {
                    books.add(cursor.getString(1));
                } while (cursor.moveToNext());
            }
        }
            }


            }




Custom Adopter

package bible.swordof.God;

import android.app.Activity;
import android.content.Context;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ArrayAdapter;
import android.widget.ImageView;
import android.widget.TextView;

import com.amulyakhare.textdrawable.TextDrawable;
import com.amulyakhare.textdrawable.util.ColorGenerator;

import java.util.ArrayList;
import java.util.List;
import java.util.Locale;

public class ListViewAdapter extends ArrayAdapter<String> {
    private MainActivity activity;
    private List<String>bookname;
    private List<String> searchList;



    public ListViewAdapter(MainActivity context, int resource, List<String> objects) {
        super(context, resource, objects);
        this.activity = context;
        this.bookname = objects;
        this.searchList = new ArrayList<>();
        this.searchList.addAll(bookname);
    }



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

    @Override
    public String getItem(int position) {

        return bookname.get(position);


    }

    @Override
    public long getItemId(int position) {
        return position;
    }

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        ViewHolder holder;
        LayoutInflater inflater = (LayoutInflater) activity.getSystemService(Activity.LAYOUT_INFLATER_SERVICE);
        // If holder not exist then locate all view from UI file.
        if (convertView == null) {
            // inflate UI from XML file
            convertView = inflater.inflate(R.layout.item_listview, parent, false);
            // get all UI view
            holder = new ViewHolder(convertView);
            // set tag for holder
            convertView.setTag(holder);
        } else {
            // if holder created, get tag from view
            holder = (ViewHolder) convertView.getTag();
        }

        holder.bookname.setText(getItem(position));



        //get first letter of each String item
        String firstLetter = String.valueOf(getItem(position).charAt(0));


        ColorGenerator generator = ColorGenerator.MATERIAL; // or use DEFAULT
        // generate random color
        int color = generator.getColor(getItem(position));

        TextDrawable drawable = TextDrawable.builder()
                .buildRound(firstLetter, color); // radius in px



        holder.imageView.setImageDrawable(drawable);



        return convertView;
    }


    public void filter(String charText) {
        charText = charText.toLowerCase(Locale.getDefault());
        bookname.clear();
        if (charText.length() == 0) {
            bookname.addAll(searchList);
        } else {
            for (String s : searchList) {
                if (s.toLowerCase(Locale.getDefault()).contains(charText)) {
                    bookname.add(s);
                }
            }
        }
        notifyDataSetChanged();
    }


    private class ViewHolder {
        private ImageView imageView;
        private TextView bookname;

        public ViewHolder(View v) {
            imageView = (ImageView) v.findViewById(R.id.image_view);
            bookname= (TextView) v.findViewById(R.id.text);
        }
    }

    }