C#

XDocument doc = XDocument.Load(@"C:\Work\stores.xml");

            var xpath = "//store/Color[text()]" + textBox2.Text;

            var result = ((IEnumerable)doc.XPathEvaluate(xpath)).Cast<XElement>().FirstOrDefault();
            textBox1.Text = result.Value;

<pre><stores>
	<store rollNumer="170">
	    <Name>Jonh</Name>
            <Color>Pink</Color>
	    <Sell>Sugar</Sell>
	</store>

	<store rollNumer="120">
	    <Name>Tedy</Name>
            <Color>Brown</Color>
	    <Sell>Rice</Sell>
	</store>

</stores>

var query = (from r1 in dtMappedSectionNotEmpty.AsEnumerable()
                                 join r2 in dtData.AsEnumerable()
                                 on r1.Field<string>("Row").Trim().ToUpper() equals r2.Field<string>("RowCoordinate").Trim().ToUpper()
                                 join r3 in _Periods.AsEnumerable()
                                 on r2.Field<string>("StandardDate").Replace("A", string.Empty).Replace("E", string.Empty).Trim().ToUpper() equals r3.Replace("A", string.Empty).Replace("E", string.Empty).Trim().ToUpper()
                                 where r1.Field<string>("Tab").Trim().ToUpper() == strTab.Trim().ToUpper()
                                 select new BrokerData
                                 {
                                     RowNumber = r1.Field<string>("Row") ?? "0",
                                     TabName = r1.Field<string>("Matched Section") ?? "",
                                     StandardDate = r3.ToString(),
                                     BRTab = r1.Field<string>("Tab") ?? "",
                                     BRLineItem = r1.Field<string>("Broker Items") ?? "",
                                     Action = r1.Field<string>("Action") ?? "",
                                     StandardLineItem = r1.Field<string>("Matched Items") ?? "",
                                     StandardValue =r2.Field<string>("LineItemDateValue") ?? ""
                                 }).ToList();

using System;
using System.Globalization;

namespace _1002
{
    class Program
    {
        static void Main(string[] args)
        {
            double R = Convert.ToDouble(Console.ReadLine());
            double A = Math.PI * Math.Pow(R, R);
            Console.WriteLine("A = " +A.ToString("F4",CultureInfo.InvariantCulture));
           // Console.ReadLine();
        }
    }
}

I made from a database get and created in HDD. But how to read by axAcroPDF1.src (Adobe Reader)

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; }
}