private async void LvMedicaments_ItemSelected(object sender, SelectedItemChangedEventArgs e)
 {
     if (lvMedicaments.SelectedItem != null)
     {
         Medicament leMedicamentSelectionne     = (lvMedicaments.SelectedItem as Medicament);
         Pages.PageFormulationDuMedicament page = new Pages.PageFormulationDuMedicament(leMedicamentSelectionne);
         await Navigation.PushModalAsync(page);
     }
 }
 public async void RetourPageFormulationDuMedicament()
 {
     Pages.PageFormulationDuMedicament page = new Pages.PageFormulationDuMedicament(ContexteMedicament);
     await Navigation.PushModalAsync(page);
 }