How to display the selected line of the datagridview

Question

When I click on the show button I display the information after when I click on a line in the datagridview the information will be displayed in the textbox combobox and datetime picker

The problem is in the combobox of the marche because I wear id_marche (int)                 table walking and I filled the combobox by libelle_marche (string)                                          the so when I click on the datagrid view it shows me id walks in the combobox marche