checkbox in datagridview

I'mdevelopingaC#applicationthatdoeslabelprintingsothatIcanuseadatagridview,whichbringsupthelinesIneedtoprint,soInowneedtoputacheckboxtoselectthelineIneedtosendtotheprinter.

Ineedtohavetheoptiontoselectallthelinesorselectonlyoneline,I'mhavingtroublecreatingthisconditioninsidemycode.

Followthecodeontheprintbutton.

privatevoidbtnImprimir_Click(objectsender,EventArgse){if(caixa_selecao.ShowDialog()==DialogResult.Cancel)return;elseEtqFraciona.PrinterSettings=caixa_selecao.PrinterSettings;etqfrac();}}

codethatloadsthedatagridview

privatevoidListGrid()        {            stringstrSQL=@"SELECT                             SC.C2_NUM AS GUIDE,                             SB.B1_DESC THE PRODUCT,                             SC.C2_XNPAIS [COUNTRY ORIGIN],                             CONVERT (VARCHAR (10), CAST (SC.C2_XDTFAB AS DATE), 103) AS [DT. MANUFACTURING],                             CONVERT (VARCHAR (10), CAST (SC.C2_XDTVALI AS DATE), 103) AS [DT. SHELF LIFE],                             SC.C2_XLOTEF AS [LT. MANUFACTURER],                             SC.C2_XLOTE AS [LT. INTERNAL],                             SB.B1_XDCB AS DCB,                             SB.B1_XCAS AS CAS,                             CONVERT (VARCHAR (10), CAST (SB.B1_PESO AS NUMERIC (15, 3))) + SB.B1_XSEGUM AS WEIGHT,                             SC.C2_XNOMFA AS MANUFACTURER,                             CB.CB0_CODETI AS [COD. BARS]                        FROM SC2020 AS SC                        INNER JOIN SB1020 AS SB WITH (NOLOCK) ON SB.B1_COD = SC.C2_PRODUCT                        INNER JOIN CB0020 AS CB WITH (NOLOCK) ON CB.CB0_LOTE = SC.C2_XLOTE                        WHERE C2_NUM = '"+ txtGuiaFrac.Text +"' ";

        comando = new SqlCommand(strSQL, conex);

        try
        {
            SqlDataAdapter dados = new SqlDataAdapter(comando);
            DataTable dtLista = new DataTable();
            dados.Fill(dtLista);

            DGW_EtqFracionamento.DataSource = dtLista;
        }
        catch
        {
            MessageBox.Show("Não existem dados a serem encontrados");
        }

    }

Now the checkbox column in the datagridview I added by the datagridview properties in add columns.