public Dossier Creation_dossier(string name, DateTime d, Utulisateur user, int id) { if (Exists(name, user.Getlistdossier())) { return(null); } else { db.Insertdirectory(name, user.GetNom(), "RW", d, 0); Dossier newdirectory = new Dossier(name, d, user, null, db.lastindex()); user.AddtlistDossier(newdirectory); return(newdirectory); } }