using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

using System.Xml.Serialization;

using System.Xml;

using System.IO;

using System.Xml.Linq;

​

    // https://stackoverflow.com/questions/48096673/keep-sort-when-deserialize-and-serialize-xml-using-xmlserializer

​

    // Note - all constructors must be public on dotnetfiddle.net for security reasons.  This is not necessary if your code

    // executes in full trust.

​

    public abstract class StringElementBase

    {

        [XmlText]

        public string Text { get; set; }

​

        public static implicit operator string(StringElementBase element)

        {

            return element == null ? null : element.Text;

        }

    }

​

    public sealed class A : StringElementBase

    {

    }

​

    public sealed class B : StringElementBase

    {

    }

​

    [XmlRoot(ElementName = "test")]

    public class Test

    {

        [XmlElement("a", Type = typeof(A))]

        [XmlElement("b", Type = typeof(B))]

        public List<StringElementBase> Items { get; } = new List<StringElementBase>();

​

        [XmlIgnore]

        // For convenience, enumerate through the string values of the items.

        public IEnumerable<string> ItemValues { get { return Items.Select(i => (string)i); } }

​

        [XmlAttribute(AttributeName = "id")]

        public string Id { get; set; }

    }

​

    class TestClass

    {

        public static void Test()

        {

            var xml = GetXml();

​

            Console.WriteLine("\nOriginal XML:");

            Console.WriteLine(xml);

​

            var test = xml.LoadFromXml<Test>();

​

            var xml2 = test.GetXml(true);

​

            Console.WriteLine("\nRe-serialized XML:");

​

            Console.WriteLine(xml2);

​

            Assert.IsTrue(XNode.DeepEquals(XElement.Parse(xml), XElement.Parse(xml2)), "Original and re-serialized XML differ!");

​

            Console.WriteLine("\nOriginal and re-serialized XML are equivalent.");

        }

​

        static string GetXml()

        {

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

<test id=""myid"">

 <b>b1</b>

 <a>a2</a>

 <a>a1</a>

 <b>b2</b>

</test>";

            return xml;

        }

    }

​

    public class AssertionFailedException : System.Exception

    {

        public AssertionFailedException() : base() { }

​

        public AssertionFailedException(string s) : base(s) { }

    }

​

    public static class Assert

    {

        public static void IsTrue(bool value)

        {

            IsTrue(value, "failed");

        }

​

        public static void IsTrue(bool value, string message)

        {

            if (value == false)

                throw new AssertionFailedException(message ?? "failed");

        }

    }

​

    public static class XmlSerializationHelper

    {

        public static T LoadFromXml<T>(this string xmlString, XmlSerializer serial = null)

        {

            serial = serial ?? new XmlSerializer(typeof(T));

            using (var reader = new StringReader(xmlString))

            {

                return (T)serial.Deserialize(reader);

            }

        }

​

        public static string GetXml<T>(this T obj, bool omitStandardNamespaces)

        {

            return obj.GetXml(null, omitStandardNamespaces);

        }

        public static string GetXml<T>(this T obj, XmlSerializer serializer = null, bool omitStandardNamespaces = false)

        {

            XmlSerializerNamespaces ns = null;

            if (omitStandardNamespaces)

            {

                ns = new XmlSerializerNamespaces();

                ns.Add("", ""); // Disable the xmlns:xsi and xmlns:xsd lines.

            }           

            using (var textWriter = new StringWriter())

            {

                var settings = new XmlWriterSettings() { Indent = true }; // For cosmetic purposes.

                using (var xmlWriter = XmlWriter.Create(textWriter, settings))

                    (serializer ?? new XmlSerializer(obj.GetType())).Serialize(xmlWriter, obj, ns);

                return textWriter.ToString();

            }

        }

        public static string GetOuterXml(this XmlNode node, bool indent = true)

        {

            if (node == null)

                return null;

            using (var textWriter = new StringWriter())

            {

                var settings = new XmlWriterSettings

                {

                    Indent = indent,

                    OmitXmlDeclaration = true,

                };

                using (var xmlWriter = XmlWriter.Create(textWriter, settings))

                {

                    node.WriteTo(xmlWriter);

                }

                return textWriter.ToString();

            }

        }

    }

    public class Program

    {

        public static void Main()

        {

            Console.WriteLine("Roslyn 2.0 Compiler; Environment version: " + Environment.Version);

            Console.WriteLine();

​

            try

            {

                TestClass.Test();

            }

            catch (Exception ex)

            {

                Console.WriteLine("Uncaught exception: ");

                Console.WriteLine(ex);

                throw;

            }

        }

    }

​