android onclick of button get selected checkbox value issue.t

I have a listview of all install app. I am using custom adapter I save the state of my checkboxes (checked or unchecked)with sharedprefrences when user exits the application so that I can reload this state when the application restarts . i have a button in mainactivity which show the selected value of checkbox which is checked its working fine but now problem is this when app restart checkbox state is reloaded but when i click on button its show null value but checkbox is selected and it show null value what is the issue please help me.here is my code

public class Listadapter extends BaseAdapter {
    private Context mContext;
    private List<ApplicationInfo> mListAppInfo;
    private PackageManager mPackManager;
    private ArrayList<Boolean> checkList = new ArrayList<Boolean>();
    CheckBox checkBox;
    boolean index[];
    boolean[] itemChecked;
    ApplicationInfo entry;
    String[] itempkg;

    public Listadapter(Context applicationContext, List<ApplicationInfo> installedApplication, PackageManager packageManager) {
        //super(applicationContext,textViewResourceId,installedApplication);
            super();
            this.mContext = applicationContext;
            this.mListAppInfo = installedApplication;
            index = new boolean[installedApplication.size()];
            this.mPackManager = packageManager;
            for (int i = 0; i < installedApplication.size(); i++) {
            checkList.add(false);
            itemChecked = new boolean[installedApplication.size()];
                itempkg = new String[installedApplication.size()];
            }
    }
    public void setItemChecked(String[] items) {
        itempkg= items;
    }

    public void setItemCheckedd(boolean[] itemss) {
        itemChecked = itemss;
    }

    private class ViewHolder {
        ImageView ivAppIcon;
        TextView tvAppName;
        TextView tvPkgName;
        CheckBox checkBox;
    }
    @Override
    public int getCount() {
        return mListAppInfo.size();
        //return ((null != mListAppInfo) ? mListAppInfo.size() : 0);
    }

    @Override
    public Object getItem(int position) {
       // index = new boolean[mListAppInfo.size()];
        return mListAppInfo.get(position);
    }

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

    @Override
    public View getView(final int position, View convertView, ViewGroup parent) {
        // get the selected entry

        final ViewHolder holder;

      //  LayoutInflater inflater = (LayoutInflater) mContext.getLayoutInflater();
        LayoutInflater inflater = (LayoutInflater) mContext.getSystemService( Context.LAYOUT_INFLATER_SERVICE );

        if (convertView == null) {
            convertView = inflater.inflate(R.layout.list_item, null);
            holder = new ViewHolder();
        // reference to convertView
            holder.tvAppName = (TextView) convertView
                    .findViewById(R.id.textView1);
            holder.tvPkgName = (TextView) convertView
                    .findViewById(R.id.textView);
            holder.checkBox = (CheckBox) convertView
                    .findViewById(R.id.checkBox1);
            holder.ivAppIcon = (ImageView) convertView
                    .findViewById(R.id.imageView);

            convertView.setTag(holder);
            // holder.ck1.setTag(packageList.get(position));

        }
             else {

                holder = (ViewHolder) convertView.getTag();
            }
        entry = mListAppInfo.get(position);

        holder.ivAppIcon.setImageDrawable(entry.loadIcon(mPackManager));
        holder.tvAppName.setText(entry.loadLabel(mPackManager));
        holder.tvPkgName.setText(entry.packageName);
        holder.checkBox.setChecked(false);

        if (itemChecked[position])
            holder.checkBox.setChecked(true);
        else
            holder.checkBox.setChecked(false);

        holder.checkBox.setOnClickListener(new OnClickListener() {
            @Override
            public void onClick(View v) {
                // TODO Auto-generated method stub
                if (holder.checkBox.isChecked())
                {
                    itemChecked[position] = true;
                }else {
                    itemChecked[position] = false;
                } }
        });
        return convertView;
    }

}

here is mainactivity

public class MainActivity extends Activity implements OnItemClickListener {

    ListView apps;
    PackageManager packageManager;
    ArrayList<String> checkedValue;
    Button bt1;
    private ShareActionProvider mShareAction;
    ApplicationInfo pi = new ApplicationInfo();
    public static final String PREF_PROFILE3 = "pref_profile3";
    public static final String PROFILE3 = "profile3";
    Context context = this;
    SharedPreferences pkg;
    String currentApp = "NULL";
    CheckBox cb;
    Listadapter Adapter = null;
    boolean[] itemCheckedd;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        itemCheckedd = new boolean[Utilities.getInstalledApplication(this).size()];

        bt1 = (Button) findViewById(R.id.button1);
        apps = (ListView) findViewById(R.id.listView1);
        apps.setChoiceMode(ListView.CHOICE_MODE_SINGLE);

        packageManager = getPackageManager();
        checkedValue = new ArrayList<String>();



        final String[] items = new String[Utilities.getInstalledApplication(this).size()];
        final boolean[] itemss = new boolean[Utilities.getInstalledApplication(this).size()];

        SharedPreferences preferences = context.getSharedPreferences("YOUR_APP_NAME", Context.MODE_PRIVATE);

        for (int i = 0; i < Utilities.getInstalledApplication(this).size(); ++i) {
            itemss[i] = preferences.getBoolean("checkbox_" + i, false);
        }
        for (int i = 0; i < Utilities.getInstalledApplication(this).size(); ++i) {
            items[i] = preferences.getString("pkgname" + i, "");
            Toast.makeText(MainActivity.this, "all" + items[i], Toast.LENGTH_LONG).show();
        }
       //
       // Listadapter Adapter = new Listadapter(this, Utilities.getInstalledApplication(this), packageManager);
        Adapter = new Listadapter(this, Utilities.getInstalledApplication(this), packageManager);
      //  Adapter.setItem(pkg);
        Adapter.setItemChecked(items);
        Adapter.setItemCheckedd(itemss);
        apps.setAdapter(Adapter);

        apps.setOnItemClickListener(this);

        bt1.setOnClickListener(new View.OnClickListener() {

            @Override
            public void onClick(View v) {
                // TODO Auto-generated method stub

                Toast.makeText(MainActivity.this, "all"+":" + checkedValue, Toast.LENGTH_LONG).show();
            }
        });
    }
    @Override
    public void onItemClick(AdapterView<?> arg0, View v, int position, long arg3) {
        // TODO Auto-generated method stub
        cb = (CheckBox) v.findViewById(R.id.checkBox1);
        TextView tv = (TextView) v.findViewById(R.id.textView);
        pi = (ApplicationInfo) arg0.getItemAtPosition(position);
        cb.performClick();
        if (cb.isChecked()) {
            checkedValue.add(tv.getText().toString());
            itemCheckedd[position] = true;
           // Toast.makeText(MainActivity.this, "all" + position, Toast.LENGTH_LONG).show();
            SharedPreferences preferences = context.getSharedPreferences("YOUR_APP_NAME", Context.MODE_PRIVATE);
            SharedPreferences.Editor edit = preferences.edit();
            edit.putBoolean("checkbox_" + position, true);
            edit.putString("pkgname" + position, (tv.getText().toString()));
            edit.commit();

        } else if (!cb.isChecked()) {
            checkedValue.remove(tv.getText().toString());
            SharedPreferences preferences = context.getSharedPreferences("YOUR_APP_NAME", Context.MODE_PRIVATE);
            SharedPreferences.Editor edit = preferences.edit();
            edit.putBoolean("checkbox_" + position, false);
            edit.putString("pkgname" + position, "");
            edit.commit();

        }

      }

}