C#

using System;

namespace test_cs
{
    class Program
    {
        static double calc(double n, double m)
        {
            return (n * m);
        }

        static void Main(string[] args)
        {
            Console.WriteLine("Welcome to calculator 1.0");
            Console.Write("Enter calculations:");
            double num1, num2;
            char oper;
            num1 = Convert.ToInt32(Console.Read());
            oper = Convert.ToChar(Console.Read());
            num2 = Convert.ToInt32(Console.Read());

            Console.WriteLine("{0} {1} {2}", num1, oper, num2);
            Console.ReadLine();
            Console.ReadLine();
        }

    }
}

std::cin >> num1 >> oper >> num2;

<pre lang="c#">

<pre>BELayer:
public string quantity { get; set; }
public string prod_id { get; set; }
public string party_id { get; set; }  


DALayer page code:
//command for auto fill data into quantity table;
        public SqlDataReader autofillparty_id(BEL beobj)
        {
            try
            {
                
                cmd = new SqlCommand("select * from product where prod_id='" + beobj.prod_id + "'", con);
                cmd.CommandType = CommandType.StoredProcedure;
                cmd.CommandText = "spsearchpartyid";
                cmd.Parameters.AddWithValue("@prod_id", beobj.prod_id);
                con.Open();
                SqlDataReader sdr = cmd.ExecuteReader(CommandBehavior.CloseConnection);
                return sdr;
     
            }
            catch (Exception ex)
            {
                throw ex;
            }

            finally 
            {
               con.Close();
            }
        }


BALayer code
//command for autofill data into table quantity..
        public SqlDataReader autofillquantity(BEL beobj)
        {
            try
            {
                return daobj.autofillparty_id(beobj);
            }
            catch (Exception ex)
            {
                throw ex;
            }
        }

Main Page code::
private void button1_Click(object sender, EventArgs e)
        {
          if (baobj.autofillquantity(beobj).Read())
            {
                txtboxpartyidquant.Text = (beobj.party_id.ToString());
                
            }

        }
 this code is not working i know problem is in my main page but i don't know how can i solve this problem please help me ...

public class Order : IValidateObject
{
    public int Id { get; set; }
    public int ItemId { get; set; }
    public int Quantity { get; set; }

    public IEnumerable<ValidationResult> Validate(ValidationContext validationContext)
    {
        var item = DbContext.Items.Find(ItemId); // <-- What about this?
        if (Quantity % item.Multiple != 0)
            yield return new ValidationResult("Quantity not multiple of item", new[] {Quantity});
    }
}

public class Item
{
    public int Id { get; set; }
    public int Multiple { get; set; }
}

public class Person
{
    public int PersonId { get; set; } //Primary key
    //Other Properties. 
    public int ParentId { get; set; } //ForignKey of another Person
    public virtual ICollection<Person> People { get; set; }//Clooection of the same class.
}