public static void SearchByRefCommand()   //_ SEARCHING Article.
        {
            Console.WriteLine("------------------------------");
            Console.WriteLine("SEARCHING Article ------------");
            Console.WriteLine("------------------------------");


            int Ref = 0;    //_ Article Reference.


            bool correct = false;   //_ Reference Filling.
            do
            {   //_ Entry Type Verification.
                Console.Write("Enter the Article Reference : _");
                try
                {
                    Ref = Int32.Parse(Console.ReadLine());
                    correct = true;
                }
                catch (Exception ex)
                {
                    Console.WriteLine(ex.Message);
                }
            } while (correct == false);


            Article searchedArticle = null;   //_ Searching for the Article.
            try
            {
                searchedArticle = ArticleDAL.SelectByRef(Ref);
                Console.WriteLine("Searching Done Successfully ..");
            }
            catch (Exception ex)
            {
                Console.WriteLine(ex.Message);
            }


            if (searchedArticle != null)  //_ null : Article Not Found.
                Show(searchedArticle);
            else
                Console.WriteLine("Article Not Found.");

        }
        public static void DeleteCommand()      //_ SUPRESSION d'un Article.
        {
            Console.WriteLine("------------------------------");
            Console.WriteLine("DELETING Article -------------");
            Console.WriteLine("------------------------------");


            int Ref = 0;    //_ Reference.


            //_ Reference Filling.
            bool correct = false;
            do
            {
                Console.Write("Enter the Article Reference : _");
                try //_ Type Verification.
                {
                    Ref = Int32.Parse(Console.ReadLine());
                    correct = true;
                }
                catch (Exception ex)
                {
                    Console.WriteLine(ex.Message);
                }
            } while (correct == false);


            Article searchedArticle = null;   //_ Searching.
            try
            {
                searchedArticle = ArticleDAL.SelectByRef(Ref);
            }
            catch (Exception ex)
            {
                Console.WriteLine(ex.Message);
            }


            if (searchedArticle != null)
            {
                Show(searchedArticle);    //_ Search Result Printing.


                //_ Deleting Confirmation.
                char choice = 'n';
                correct = false;
                do  //_ Type Verification.
                {
                    Console.Write("\nDo you Confirm Deleting ? [(Y): Yes / (n): no] _");
                    try
                    {
                        choice = char.Parse(Console.ReadLine());
                        correct = true;
                    }
                    catch (Exception ex)
                    {
                        Console.WriteLine(ex.Message);
                    }
                } while (correct == false);


                if (choice == 'Y')   //_ Deleting Confirmed.
                {
                    try
                    {
                        ArticleDAL.Delete(Ref);
                        Console.WriteLine("Article Deleted Successfully ..");
                    }
                    catch (Exception ex)
                    {
                        Console.WriteLine(ex.Message);
                    }
                }
                else
                    Console.WriteLine("No Article Deleting..");
            }
            else
                Console.WriteLine("Article Not Found");

        }
        public static void ModificationCommand()       //_ MODIFICATION of Article.
        {
            Console.WriteLine("------------------------------");
            Console.WriteLine("MODIFICATION of Article ------");
            Console.WriteLine("------------------------------");


            int Ref = 0;    //_ Article Reference.


            bool correct = false;   //_ Reference Filling.
            do
            {   //_ Type Verification.
                Console.Write("Enter the Article Reference : _");
                try
                {
                    Ref = Int32.Parse(Console.ReadLine());
                    correct = true;
                }
                catch (Exception ex)
                {
                    Console.WriteLine(ex.Message);
                }
            } while (correct == false);


            Article searchedArticle = null; //_ Searching for the Article.
            try
            {
                searchedArticle = ArticleDAL.SelectByRef(Ref);
                Console.WriteLine("Recherche Effectuée ..");
            }
            catch (Exception ex)
            {
                Console.WriteLine(ex.Message);
            }


            if (searchedArticle != null)  //_ null : Article introuvable.
            {
                Show(searchedArticle);    //_ Affichage de l'Article Trouvé.
                Console.WriteLine();

                //_ Saisie des informations manquantes.
                Article updatedArticle = new Article(Ref, "", 0);

                Console.Write("--Designation : _"); //_ Designation Filling.
                updatedArticle.Designation = Console.ReadLine();

                correct = false;    //_ Price Filling.
                do
                {   //_ Type Verification.
                    Console.Write("--Prce : _");
                    try
                    {
                        updatedArticle.Price = float.Parse(Console.ReadLine(), CultureInfo.InvariantCulture);
                        correct = true;
                    }
                    catch (Exception ex)
                    {
                        Console.WriteLine(ex.Message);
                    }
                } while (correct == false);


                Show(updatedArticle);    //_ Modification Printing.
                Console.WriteLine();

                correct = false;    //_ Confirmation of the Modifications.
                char choice = 'n';
                do //_ Type Verification.
                {
                    Console.Write("\nDo you Confirm the modifications ? [(Y): Yes / (n): no] _");
                    try
                    {
                        choice = char.Parse(Console.ReadLine());
                        correct = true;
                    }
                    catch (Exception ex)
                    {
                        Console.WriteLine(ex.Message);
                    }
                } while (correct == false);


                if (choice == 'Y')   //_ Verification de la confirmation.
                {
                    //_ Mise à jour.
                    try
                    {
                        ArticleDAL.Update(Ref, updatedArticle);
                        Console.WriteLine("Article Modified Successfully ..");
                    }
                    catch (Exception ex)
                    {
                        Console.WriteLine(ex.Message);
                    }
                }
                else
                    Console.WriteLine("No Modification Added ..");

            }
            else
                Console.WriteLine("Article Not Found");

        }