using System;

using System.Collections.Generic;

using System.IO;

using System.Xml.Serialization;

​

public static class Program

{

    public static void Main(string[] args)

    {

        var main = new CMainClass

        {

            Parameters =

            {

                new Param("number", "123"),

                new Param("text", "lorem ipsum"),

                new Param("price", "23.50")

            }

        };

​

        var xml = main.GetXml();

​

        Console.WriteLine(xml);

    }

}

​

public class Param

{    

    public Param(string name, string value)

    {

        Name = name;

        Value = value;

    }

​

    public Param()

    {

    }

​

    [XmlAttribute]

    public string Name { get; set; }

    [XmlAttribute]

    public string Value { get; set; }

}

​

public class CMainClass

{

    public List<Param> Parameters { get; } = new List<Param>();

​

    public string GetXml()

    {        

        var serializer = new XmlSerializer(typeof(CMainClass));

​

        using (var writer = new StringWriter())

        {

            serializer.Serialize(writer, this);

            return writer.ToString();

        }        

    }

}