xmlDeser/xmlDeserWin/Parser.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;
using System.Windows.Forms;
using System.Xml.Serialization;
using System.Xml;
using System.IO;

namespace xmlDeserWin
{
    class Parser
    {
        public IEnumerable<User> Deser()
        {
            List<User> users;
            using (var reader = new StreamReader("fileXML.xml"))
            {
                if (reader == null)
                    return null; 
                XmlSerializer deserializer = new XmlSerializer(typeof(List<User>),
                    new XmlRootAttribute("user_list"));
                users = (List<User>)deserializer.Deserialize(reader);

                return users;
            }


        }
    }
}