خطای NuulPointerExeption در ViewPager(حل شده)

با سلام خدمت تمام بچه های سایت من داخل برنامم دارم از viewpager استفاده میکنم ولی وقتی لیست ویو رو بهش اضافه میکنم مشکل پیش میاد و خطای NullPointerExeption میده میگه adapter خالیه درصورتیکه همون کد جای دیگه درست کار میکنه حتی برای تست کدی که خود استاد نوشتن رو هم کپی کردم ولی همون ارور رو داد کد ها رو میزارم هر کی تونست کمک کنه

ActivityMain.java AND MainPagerAdapter

 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 ActivityMain extends FragmentActivity {

    MainPagerAdapter adapter;


    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        ViewPager pager = (ViewPager) findViewById(R.id.pager);
        adapter = new MainPagerAdapter(getSupportFragmentManager());
        pager.setAdapter(adapter);

    }


    public class MainPagerAdapter extends FragmentPagerAdapter {

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


        @Override
        public Fragment getItem(int index) {

            switch (index) {
                case 0:
                    // Top Rated fragment activity
                    return new TopRatedFragment();
                case 1:
                    // Games fragment activity
                    return new GamesFragment();
                case 2:
                    // Movies fragment activity
                    return new MoviesFragment();
            }

            return null;
        }


        @Override
        public int getCount() {
            // get item count - equal to number of tabs
            return 3;
        }

    }
}

 AdapterNote.java


import java.util.ArrayList;
import android.graphics.Color;
import android.view.View;
import android.view.View.OnClickListener;
import android.view.ViewGroup;
import android.widget.ArrayAdapter;
import android.widget.CheckBox;
import android.widget.ImageView;
import android.widget.TextView;


public class AdapterNote extends ArrayAdapter<StructNote> {

    public AdapterNote(ArrayList<StructNote> array) {
        super(G.context, R.layout.adapter_notes, array);
    }


    private static class ViewHolder {

        public ViewGroup layoutRoot;
        public TextView  txtTitle;
        public TextView  txtDescription;
        public CheckBox  chkDone;
        public ImageView imgDelete;


        public ViewHolder(View view) {
            txtTitle = (TextView) view.findViewById(R.id.txtTitle);
            txtDescription = (TextView) view.findViewById(R.id.txtDescription);
            chkDone = (CheckBox) view.findViewById(R.id.chkDone);
            layoutRoot = (ViewGroup) view.findViewById(R.id.layoutRoot);
            imgDelete = (ImageView) view.findViewById(R.id.imgDelete);
        }


        public void fill(final ArrayAdapter<StructNote> adapter, final StructNote item, final int position) {
            txtTitle.setText(item.title);
            txtDescription.setText(item.description);
            chkDone.setChecked(item.done);

            imgDelete.setOnClickListener(new OnClickListener() {

                @Override
                public void onClick(View arg0) {
                    adapter.remove(item);
                }
            });
            layoutRoot.setOnClickListener(new OnClickListener() {

                @Override
                public void onClick(View arg0) {
                    //   Intent intent = new Intent(G.currentActivity, ActivityEdit.class);
                    // intent.putExtra("POSITION", position);
                    //G.currentActivity.startActivity(intent);
                }
            });
            chkDone.setOnClickListener(new OnClickListener() {

                @Override
                public void onClick(View view) {
                    CheckBox checkBox = (CheckBox) view;
                    item.done = checkBox.isChecked();

                    if (item.done) {
                        txtTitle.setTextColor(Color.RED);
                    } else {
                        txtTitle.setTextColor(Color.WHITE);
                    }
                }
            });

            if (item.done) {
                txtTitle.setTextColor(Color.RED);
            } else {
                txtTitle.setTextColor(Color.WHITE);
            }
        }
    }


    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        ViewHolder holder;

        StructNote item = getItem(position);
        if (convertView == null) {
            convertView = G.inflater.inflate(R.layout.adapter_notes, parent, false);
            holder = new ViewHolder(convertView);
            convertView.setTag(holder);
        } else {
            holder = (ViewHolder) convertView.getTag();
        }

        holder.fill(this, item, position);
        return convertView;
    }
}

G.java

import java.util.ArrayList;
import android.app.Activity;
import android.app.Application;
import android.content.Context;
import android.database.sqlite.SQLiteDatabase;
import android.os.Environment;
import android.view.LayoutInflater;


public class G extends Application {

    public static int                   position;

    public static Context               context;
    public static SQLiteDatabase        database;
    public static LayoutInflater        inflater;
    public static final String          DIR_SDCARD   = Environment.getExternalStorageDirectory().getAbsolutePath();
    public static final String          DIR_DATABASE = DIR_SDCARD + "/jomla/";
    public static final String          DIR_DATA     = DIR_DATABASE + "data.sqlite/";
    public static ArrayList<StructNote> notes        = new ArrayList<StructNote>();
    public static Activity              currentActivity;


    @Override
    public void onCreate() {
        super.onCreate();
        context = this.getApplicationContext();
        inflater = (LayoutInflater) getSystemService(Context.LAYOUT_INFLATER_SERVICE);

    }

}

StructNote.java


public class StructNote {

    public String  title;
    public String  description;
    public boolean done;

}

GameFragment.java

 import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ArrayAdapter;
import android.widget.ListView;


public class GamesFragment extends Fragment {

    public ArrayAdapter adapter;


    @Override
    public void onResume() {
        super.onResume();

        if (adapter != null) {
            adapter.notifyDataSetChanged();
        }
    }


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

        View rootView = inflater.inflate(R.layout.fragment_games, container, false);
        ListView lstContent = (ListView) rootView.findViewById(R.id.lstContent);

        adapter = new AdapterNote(G.notes);
        Log.i("Log", (String) adapter.getItem(2));
        lstContent.setAdapter(adapter);

        for (int i = 0; i < 10; i++) {
            StructNote note = new StructNote();
            note.title = "Title " + i;
            note.description = "Description " + i;
            note.done = false;

            G.notes.add(note);
        }

        adapter.notifyDataSetChanged();

        return rootView;
    }
}