using System;

using System.IO;

using System.Text;

using System.Xml.Serialization;

public class Program

{

    public static void Main()

    {

        var serializer = new ModelXmlSerializer();

        var xml = "<Model><Element attr1=\"Hello World\">5</Element></Model>";

​

        var model = serializer.Deserialize(xml);

​

        Console.WriteLine($"model.Element.Value = {model.Element.Value}; model.Element.Attr1 = \"{model.Element.Attr1}\"");

​

        var newXml = serializer.Serialize(model);

​

        Console.WriteLine($"newXml = \"{newXml}\"");

    }

}

​

public class ModelXmlSerializer : ImmutableXmlSerializer<ImmutableModel, Model>

{

    protected override ImmutableModel ConvertToImmutable(Model mutable)

    {

        return new ImmutableModel(mutable);

    }

    protected override Model ConvertToMutable(ImmutableModel immutable)

    {

        return new Model(immutable);

    }

}

​

public abstract class ImmutableXmlSerializer<TImmutable, TMutable>

{

    private readonly MyXmlSerializer<TMutable> _xmlSerializer;

​

    public ImmutableXmlSerializer()

    {

        _xmlSerializer = new MyXmlSerializer<TMutable>();

    }

​

    public TImmutable Deserialize(string xml)

    {

        return ConvertToImmutable(_xmlSerializer.Deserialize(xml));

    }

​

    public string Serialize(TImmutable obj)

    {

        return _xmlSerializer.Serialize(ConvertToMutable(obj));

    }

    protected abstract TImmutable ConvertToImmutable(TMutable mutable);

    protected abstract TMutable ConvertToMutable(TImmutable immutable);

}

​

public class MyXmlSerializer<T>

{

    private readonly XmlSerializer _xmlSerializer;

​

    public MyXmlSerializer()

    {

        _xmlSerializer = new XmlSerializer(typeof(T));

    }

​

    public T Deserialize(string xml)

    {

        using (TextReader reader = new StringReader(xml))

        {

            return (T)_xmlSerializer.Deserialize(reader);

        }

    }

​

    public string Serialize(T obj)

    {

        var builder = new StringBuilder();

        using (TextWriter writer = new StringWriter(builder))

        {

            _xmlSerializer.Serialize(writer, obj);

        }

        return builder.ToString();

    }

}

​

public class ImmutableModel

{

    public ImmutableModel(Model model)

    {

        this.Element = new ImmutableElement(model.Element);

    }

    public ImmutableElement Element { get; private set; }

}

​

public class ImmutableElement

{

    public ImmutableElement(Element element)

    {

        this.Value = element.Value;

        this.Attr1 = element.Attr1;

    }

    public int Value { get; private set; }

​

    public string Attr1 { get; private set; }

}

​

[XmlRoot("Model")]

public class Model

{   

    public Model()

    {

    }

    public Model(ImmutableModel model)

    {

        this.Element = new Element(model.Element);

    }

    [XmlElement("Element")]

    public Element Element { get; set; }

}

​

public class Element

{

    public Element()

    {

    }

    public Element(ImmutableElement element)

    {

        this.Value = element.Value;

        this.Attr1 = element.Attr1;

    }

    [XmlText]

    public int Value { get; set; }

​

    [XmlAttribute("attr1")]

    public string Attr1 { get; set; }

}