using System;

using System.Xml;

using System.Xml.Serialization;

using System.IO;

using System.Threading.Tasks;

using System.Text;

public class Program

{

    public static void Main()

    {

        var xml = 

            @"<?xml version=""1.0"" encoding=""utf-8""?>

              <x:somefile xmlns:x=""http://www.some.com/xmlns/archivefile20010605"">

                <x:somefield>

                    <x:somegroup x:itemid=""289001000377735"" />

                </x:somefield>

              </x:somefile>";

​

        var archiveFile = Deserialize(xml);

        archiveFile.Dump();

    }

    static SomeFile Deserialize(string xml)

    {

        using var streamReader = new StringReader(xml);

        using var xmlReader = XmlReader.Create(streamReader, null);

        var serializer = new System.Xml.Serialization.XmlSerializer(typeof(SomeFile));

        return (SomeFile)serializer.Deserialize(xmlReader);

​

    }

}

​

[XmlRoot(ElementName = "somefile", Namespace = "http://www.some.com/xmlns/archivefile20010605")]

public class SomeFile

{

    [XmlElement(ElementName = "somefield", Namespace = "http://www.some.com/xmlns/archivefile20010605")]

    public SomeField SomeField { get; set; }

​

}

​

[XmlRoot(ElementName = "somefield", Namespace = "http://www.some.com/xmlns/archivefile20010605")]

public class SomeField

{

    [XmlElement(ElementName = "somegroup", Namespace = "http://www.some.com/xmlns/archivefile20010605")]

    public SomeGroup SomeGroup { get; set; }

}

​

​

[XmlRoot(ElementName = "somegroup", Namespace = "http://www.some.com/xmlns/archivefile20010605")]

public class SomeGroup

{

    [XmlAttribute(AttributeName = "itemid", Namespace = "http://www.some.com/xmlns/archivefile20010605")]

    public string ItemId { get; set; }

​

}

​

​