Android - agregar checkbox en un archivo ya creado

CheckBoxAdapter clase = new CheckAdapter(this,list,listview1);

clase.getclases();

import android.app.*;

import android.content.*;

import android.opengl.*;

import android.view.*;

import android.widget.*;

import android.widget.LinearLayout.*;

import java.util.*;

public class CheckboxAdapter extends BaseAdapter

{

    private Context mContext;

    private List<StringIndexOutOfBoundsException> mTasksList;

    public CheckboxAdapter(Context context, List<String> mTasksList, ViewGroup v)

	{

		mContext = context;

		getView(0,  null  ,null);

	}

    private static class ViewHolder {

        TextView text;

        CheckBox check;

		ListView listvie;

    }

    @Override

    public View getView(final int position, View convertView, ViewGroup parent)

	{

        final ViewHolder holder;

		View rowView = convertView;

        if (rowView == null)

		{

			LayoutInflater inflater = ((Activity)mContext).getLayoutInflater();

            rowView = inflater.inflate(R.layout.datepiker, parent, true);

			final LinearLayout attractedTo = (LinearLayout)rowView.findViewById(R.id.yourlayout);

			for(int i=0;i<11;i++){

				CheckBox cb= new CheckBox(mContext);

				cb.setLayoutParams(new LinearLayout.LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT, 1f));

				cb.setText("textbox");

				attractedTo.addView(cb,i);

				Toast.makeText(mContext, "entre nueve 2", Toast.LENGTH_SHORT).show();

			}

        }

        else {

           holder = (ViewHolder) convertView.getTag();

        }

        return convertView;

    }

    @Override

    public int getCount() {

        return this.mTasksList.size();

    }

    @Override

    public Object getItem(int position) {

        return this.mTasksList.get(position);

    }

    @Override

    public long getItemId(int position) {

        return position;

    }

}