public void DoAction(string saisie)
{
switch (saisie.ToUpper())
{
case "5":
_CityService.AddManyCities(1000000);
break;
case "6":
_CityService.ClearCities();
_CityService.AddManyCities(1000000);
break;
case "7":
_CityService.ClearCities();
break;
case "8":
_CityService.SaveToFile(@"./cities.csv");
break;
}
}