C#

class Program
    {
        static List<IProduct> productList = new List<IProduct>();
        static void Main(string[] args)
        {
            Console.WriteLine("What product would you like to purchase");
            Console.WriteLine("1 Xbox");
            Console.WriteLine("2 Ps3");
            Console.Write("Number: ");
            char choice = Console.ReadLine()[0];
            Choice ch = Makedescision(choice);
            EvaluateDescision(ch);
            Console.ReadKey();
        }
        enum Choice { xbox = 1, ps3 = 2, nothing };

        static Choice Makedescision(char input)
        {
            if (input.Equals('1'))
            {
                return Choice.xbox;
            }
            else if (input.Equals('2'))
            {
                return Choice.ps3;
            }

            return Choice.nothing;

        }
        static void EvaluateDescision(Choice ch)
        {
            if (ch == Choice.xbox)
            {
                MakeNewXbox();
            }
            else if (ch == Choice.ps3)
            {
                MakeNewPs3();
            }
        }

        static void MakeNewXbox()
        {
            Xbox product = new Xbox();
            Console.WriteLine("Name your xbox");
            product.Name = Console.ReadLine();
            product.quantity = 2;
            product.Cost = 129.99m;
            productList.Add(product);
            ShowDetail(0);

        }
        static void MakeNewPs3()
        {
            Ps3 product = new Ps3();
            Console.WriteLine("Is new?");
            bool isNew = bool.Parse(Console.ReadLine());
            product.IsNew = isNew;
            product.Cost = 129.99m;
            productList.Add(product);
            ShowDetail(0);

        }

        static void ShowDetail(int i)
        {
            int quantity;
            bool detail;
            IProduct prod = (IProduct)productList[i];
            try
            {
                quantity = ((Xbox)(prod)).quantity;
                Console.WriteLine("quantity is " + quantity);
                
            }catch(Exception e)
            {
            }
            try
            {
                detail = ((Ps3)(prod)).IsNew;
                Console.WriteLine("is new? " + detail);
            }
            catch (Exception e)
            {
            }


        }
        
    }

PermissionSet ps = new PermissionSet(PermissionState.None);
     ps.AddPermission(new SecurityPermission(SecurityPermissionFlag.Execution));
     FileIOPermission fP = new FileIOPermission(PermissionState.None);
     fP.AllFiles = FileIOPermissionAccess.NoAccess;
     fP.AddPathList(FileIOPermissionAccess.PathDiscovery | FileIOPermissionAccess.Read, Environment.CurrentDirectory);


     ps.AddPermission(fP);



         AppDomainSetup ads = new AppDomainSetup();
         ads.ApplicationBase = AppDomain.CurrentDomain.SetupInformation.ApplicationBase;
         AppDomain domain = AppDomain.CreateDomain("Plugins", AppDomain.CurrentDomain.Evidence, ads, ps, CreateStrongName(System.Reflection.Assembly.GetExecutingAssembly()));
         IPlugin finder = (IPlugin)domain.CreateInstanceFromAndUnwrap("MyPluginTest.dll", "MyPluginTest.IPluginTest");
         finder.PerformAction(null);

private void openExcel()
{
            string connectionString = @"Provider=Microsoft.ACE.OLEDB.12.0;Data Source=""C:\MyLocation\myFile.xls"";Extended Properties=""Excel 12.0;HDR=NO;""";
            OleDbConnection excelConnection = new OleDbConnection(connectionString);
            excelConnection.Open();

            string strSQL = "SELECT * FROM [Sheet1$]";

            OleDbCommand dbCommand = new OleDbCommand(strSQL, excelConnection);
            OleDbDataAdapter dataAdapter = new OleDbDataAdapter(dbCommand);

            // create data table
            DataTable dTable = new DataTable();
            dataAdapter.Fill(dTable);

            aListBoxControl.DataSource = dTable;

            // dispose used objects
            dTable.Dispose();
            dataAdapter.Dispose();
            dbCommand.Dispose();

            excelConnection.Close();
            excelConnection.Dispose();
        }

[DllImport("BTDataAccess.dll")]
        static extern uint BTReadBu( [In, MarshalAs(UnmanagedType.BStr)] string filePath);