Add row in datagrid after select from SQL C#

Add row in datagrid after select from sql query

First time when select is empty row, second is full row

Some help please

Need when select from db value to insert in datagrid

Query is ok

private void prijavaAction()
        {

            int sno = dataGridView1.Rows.Count + 1;

            SqlConnection con = new SqlConnection(cs);

                if (textBox1.Text.All(char.IsDigit))

                {
                    string queryString = "select bar_kod, ime, cijena_sa_porezom from roba_usluge WHERE bar_kod = '" + textBox1.Text + "'";// pronaci artikl u bazi              
                    using (SqlConnection connection = new SqlConnection(cs))
                    {
                        SqlCommand command = new SqlCommand(queryString, connection);
                        connection.Open();
                        SqlDataReader reader = command.ExecuteReader();


                        if (reader.Read())

                        {
                            for (int i = 1; i < dataGridView1.Rows.Count; i++)
                            {
                                dataGridView1.Rows[i].Cells["redni_broj"].Value = i;
                                dataGridView1.Rows[i].Cells["bar_kod"].Value = reader["bar_kod"].ToString();
                                dataGridView1.Rows[i].Cells["naziv_artikla"].Value = reader["ime"].ToString();
                                dataGridView1.Rows[i].Cells["cijena"].Value = reader["cijena_sa_porezom"].ToString();
                            }


                        // dataGridView1.Rows.Add(sno, nazivartikla, 1, cijena, cijena);
                         dataGridView1.Rows.Add();


                        reader.Close();


                        }
                        else
                        {
                            MessageBox.Show("Bar kod ne postoji u bazi!", "Obavještenje", MessageBoxButtons.OK, MessageBoxIcon.Information);
                            textBox1.Text = "";


                        }
                    }

                }

                else
                {
                    MessageBox.Show("Bar kod ne postoji ili nije bar kod!", "Obavještenje", MessageBoxButtons.OK, MessageBoxIcon.Information);
                    textBox1.Text = "";
                }
}