List<DataGridViewRow> selectedRows = (from row in DataGridViewFamille.Rows.Cast<DataGridViewRow>()
                                              where Convert.ToBoolean(row.Cells["checkBoxColumn"].Value) == true
                                              select row).ToList();


        if (MessageBox.Show(string.Format("Do you want to delete {0} rows?", selectedRows.Count), "Confirmation", MessageBoxButtons.YesNo) == DialogResult.Yes)
        {
            //delete Nature de Charge before delete Famille
            foreach (DataGridViewRow row in selectedRows)
            {
                try
                {
                    using (SqlConnection con = new SqlConnection(connstring))
                    {
                        con.Open();
                        using (SqlCommand command = new SqlCommand("DELETE NatureCharge FROM NatureCharge n INNER JOIN Famille f on n.IdFam = f.IdFam WHERE IdNat = @IdNat", con))
                        {
                            command.Parameters.AddWithValue("@IdFam", row.Cells["IdFam"].Value);
                            command.ExecuteNonQuery();
                        }
                        con.Close();
                    }
                }
                catch (SystemException ex)
                {
                    MessageBox.Show(string.Format("An error occurred: {0}", ex.Message));
                }

            }

            //Delete Famille
            foreach (DataGridViewRow row in selectedRows)
            {
                using (SqlConnection con = new SqlConnection(connstring))
                {
                    using (SqlCommand cmd = new SqlCommand("DELETE FROM Famille WHERE IdFam = @IdFam", con))
                    {
                        cmd.CommandType = CommandType.Text;
                        cmd.Parameters.AddWithValue("@IdFam", row.Cells["IdFam"].Value);
                        con.Open();
                        cmd.ExecuteNonQuery();
                        con.Close();
                    }
                }
            }

            //Update the datagridview
            this.BindGrid();
        }