how to check file from sdcard selected or not

I am creating an app in which i can fetch files from sdcard and delete it, for deleting files I'm using checkbox but when I'm scrolling it's state gets changed. How can i check if that file is checked or not? Should i create setters and getters for it?

@Override
public View getView(final int position, View convertView, ViewGroup parent)
{
    // TODO Auto-generated method stub
    LayoutInflater inflater = ((Activity)context).getLayoutInflater();
    convertView = inflater.inflate(R.layout.row, parent, false); 

    final CheckBox cb = (CheckBox) convertView.findViewById(R.id.checkBox1);
    TextView tv = (TextView) convertView.findViewById(R.id.textView1);

    tv.setText(modelItems.get(position));

    cb.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener(){

            @Override
            public void onCheckedChanged(CompoundButton p1, boolean isChecked)
            {
                // TODO: Implement this method
                if (p1.isChecked())
                {
                    isChecked = true;
                    cb.setChecked(true); 
                }
                else
                {
                    isChecked = false;
                    cb.setChecked(false);
                }
            }
        });

    return convertView;
}