using System;

using System.Collections.Generic;

using System.Text;

using System.Linq;

using System.Xml.Serialization;

using System.Xml;

using System.Xml.Linq;

using System.IO;

using System.Data;

using System.Runtime.Serialization;

using System.Runtime.Serialization.Formatters.Binary;

using System.IO.Compression;

using System.Reflection;

​

using NUnit.Framework; //NUnit.Framework.AssertionException

​

//https://stackoverflow.com/questions/58331559/could-jsondocument-be-used-as-contractresolver

​

    public class TestClass

    {

        public static void Test()

        {

            var fooNs = "http://www.example.com/xmlns/foo-version1";

            var defNs = "http://www.example.com/xmlns";

            var doc = new XmlDocument();

​

            // Create and add the root element

            var root = doc.CreateElement("foo", "document", fooNs);

            doc.AppendChild(root);

​

            // Add the default namespace (do note the root element is not in this namespace)

            var defAttr = doc.CreateAttribute("xmlns");

            defAttr.Value = defNs;

            root.Attributes.Append(defAttr);

            // Create the <foo:bar> element

            var bar = doc.CreateElement("foo", "bar", fooNs);

            var bazAttr = doc.CreateAttribute("foo", "baz", fooNs);

            bazAttr.Value = XmlConvert.ToString(true);

            bar.Attributes.Append(bazAttr);

            // Add it to the root

            root.AppendChild(bar);

​

#if false           

            // The following is redundant as the framework (XmlWriter) will add the necessary

            // xmlns:foo attribute as the XmlDocument is being written.  If you need to do it anway 

            // (e.g. to control the order) you can do it as follows.

            // (But note that XML attributes are unordered according to the XML specification, for details

            // see https://stackoverflow.com/questions/33746224/in-xml-is-the-attribute-order-important)

            var xmlnsNs = "http://www.w3.org/2000/xmlns/";

​

            var fooAttr = doc.CreateAttribute("xmlns", "foo", xmlnsNs);

            fooAttr.Value = fooNs;

            root.Attributes.Append(fooAttr);

#endif

​

            var xml = doc.GetOuterXml();

            Console.WriteLine(xml);

            Assert.IsTrue(XNode.DeepEquals(XElement.Parse(xml), XElement.Parse(GetRequiredXml())));

        }

        static string GetRequiredXml()

        {

            return @"<foo:document xmlns=""http://www.example.com/xmlns"" xmlns:foo=""http://www.example.com/xmlns/foo-version1"">

    <foo:bar foo:baz=""true"" />

</foo:document>";

        }

    }

​

    public static class XmlSerializationHelper

    {

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

        {

            if (node == null)

                return null;

            using (var textWriter = new StringWriter())

            {

                var settings = new XmlWriterSettings { Indent = indent, OmitXmlDeclaration = omitXmlDeclaration };

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

                    node.WriteTo(xmlWriter);

                return textWriter.ToString();

            }

        }

    }

    public class Program

    {

        public static void Main()

        {

            Console.WriteLine("Environment version: {0} ({1})", System.Runtime.InteropServices.RuntimeInformation.FrameworkDescription , GetNetCoreVersion());

            Console.WriteLine();

​

            try

            {

                TestClass.Test();

            }

            catch (Exception ex)

            {

                Console.WriteLine("Failed with unhandled exception: ");

                Console.WriteLine(ex);

                throw;

            }

        }

        public static string GetNetCoreVersion()

        {

            //https://techblog.dorogin.com/how-to-detect-net-core-version-in-runtime-ecd65ad695be

            //

            var assembly = typeof(System.Runtime.GCSettings).GetTypeInfo().Assembly;

            var assemblyPath = assembly.CodeBase.Split(new[] { '/', '\\' }, StringSplitOptions.RemoveEmptyEntries);

            int netCoreAppIndex = Array.IndexOf(assemblyPath, "Microsoft.NETCore.App");

            if (netCoreAppIndex > 0 && netCoreAppIndex < assemblyPath.Length - 2)

                return assemblyPath[netCoreAppIndex + 1];

            return null;

        }

    }

​