如何从BaseAdapter的Listview中选择所有/取消选择所有复选框

private class BaseAdpterSendToServer extends BaseAdapter{

        String latti,calulationVal;
        String longi;
        String name;


        public BaseAdpterSendToServer(Context context) {
        layoutInflater = LayoutInflater.from(context);
        }

        @Override
        public int getCount() {

            return AndroidCamera.imagelistcount;
        }

        @Override
        public Object getItem(int arg0) {
            return arg0;
        }

        @Override
        public long getItemId(int arg0) {
            return arg0;
        }

        @Override
        public View getView(int position, View convertView, ViewGroup arg2) {

            viewHolder holder;

            if(convertView==null){
                holder  = new viewHolder();
                convertView =layoutInflater.inflate(R.layout.row_send_to_server, null);

                holder.showImage = (ImageView)convertView.findViewById(R.id.imgView);               
                holder.txtCalulation = (TextView)convertView.findViewById(R.id.txtCalualtionVal);
                holder.txtLatti = (TextView)convertView.findViewById(R.id.txtValLat);
                holder.txtLongi = (TextView)convertView.findViewById(R.id.txtValLong);
                holder.txtName = (TextView)convertView.findViewById(R.id.txtValName);
                holder.checkBox = (CheckBox)convertView.findViewById(R.id.chkBox);
                convertView.setTag(holder);
            }
            else{
                holder =(viewHolder)convertView.getTag();
            }
            int pos = 0;
            DBConnect d1 = new DBConnect(getApplicationContext(),\"colorCode.db\");

            pos = position+1;
            Cursor c = d1.selectedImageId(pos);


            String path = c.getString(1);
             calulationVal = c.getString(2);
             String s= calulationVal.toString();
             latti = c.getString(3);
             longi = c.getString(4);
             name = c.getString(5);
                d1.close();

          Bitmap b1 = BitmapFactory.decodeFile(path);


            System.out.println(\"THE BITMAP ISK ----- \"+b1);

            holder.showImage.setImageBitmap(b1);
            holder.txtCalulation.setText(\"\"+s);
            holder.txtLatti.setText(\"\"+latti);
            holder.txtLongi.setText(\"\"+longi);
            holder.txtName.setText(\"\"+name);

            bt_f_unsel.setOnClickListener(new OnClickListener() {


                }
            });

            return convertView;
        }

        class viewHolder{
            TextView txtCalulation ,txtLatti, txtLongi,txtName;
            ImageView showImage;
            CheckBox checkBox;
        }