using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

using System.Xml.Serialization;

using System.Xml;

using System.IO;

using System.Diagnostics;

using System.Collections.ObjectModel;

using System.Threading;

using System.ComponentModel;

using System.Xml.Linq;

using System.Reflection;

using System.Data;

using System.Xml.Schema;

using System.Net;

using System.Xml.XPath;

using System.Globalization;

using System.Collections;

​

namespace Question42490161

{

​

    // https://stackoverflow.com/questions/42490161/how-to-serialize-listlistobject

​

    namespace List

    {

        [System.SerializableAttribute()]

        [System.ComponentModel.DesignerCategoryAttribute("code")]

        [System.Xml.Serialization.XmlTypeAttribute(AnonymousType = true)]

        public partial class OxFordDefinition_perGroup

        {

​

            private string _GroupDescField;

​

            private string _GroupSenseField;

​

            private string _GroupGrammerField;

​

            /// <remarks/>

            public string _GroupDesc

            {

                get

                {

                    return this._GroupDescField;

                }

                set

                {

                    this._GroupDescField = value;

                }

            }

​

            /// <remarks/>

            public string _GroupSense

            {

                get

                {

                    return this._GroupSenseField;

                }

                set

                {

                    this._GroupSenseField = value;

                }

            }

​

            /// <remarks/>

            public string _GroupGrammer

            {

                get

                {

                    return this._GroupGrammerField;

                }

                set

                {

                    this._GroupGrammerField = value;

                }

            }

​

            private List<OxFordDefinition_perGroup_perMainExample_perSubExample> _perMainExampleField;

​

            /// <remarks/>

            [System.Xml.Serialization.XmlArrayItemAttribute("_perSubExample", IsNullable = false)]

            public List<OxFordDefinition_perGroup_perMainExample_perSubExample> _perMainExample

            {

                get

                {

                    return this._perMainExampleField;

                }

                set

                {

                    this._perMainExampleField = value;

                }

            }

        }

    }

​

    namespace Original

    {

        [System.SerializableAttribute()]

        [System.ComponentModel.DesignerCategoryAttribute("code")]

        [System.Xml.Serialization.XmlTypeAttribute(AnonymousType = true)]

        public partial class OxFordDefinition_perGroup

        {

​

            private string _GroupDescField;

​

            private string _GroupSenseField;

​

            private string _GroupGrammerField;

​

            private OxFordDefinition_perGroup_perMainExample_perSubExample[] _perMainExampleField;

​

            /// <remarks/>

            public string _GroupDesc

            {

                get

                {

                    return this._GroupDescField;

                }

                set

                {

                    this._GroupDescField = value;

                }

            }

​

            /// <remarks/>

            public string _GroupSense

            {

                get

                {

                    return this._GroupSenseField;

                }

                set

                {

                    this._GroupSenseField = value;

                }

            }

​

            /// <remarks/>

            public string _GroupGrammer

            {

                get

                {

                    return this._GroupGrammerField;

                }

                set

                {

                    this._GroupGrammerField = value;

                }

            }

​

            /// <remarks/>

            [System.Xml.Serialization.XmlArrayItemAttribute("_perSubExample", IsNullable = false)]

            public OxFordDefinition_perGroup_perMainExample_perSubExample[] _perMainExample

            {

                get

                {

                    return this._perMainExampleField;

                }

                set

                {

                    this._perMainExampleField = value;

                }

            }

        }

    }

​

    public class OxFordDefinition_perGroup_perMainExample_perSubExample

    {

    }

​

    class TestClass

    {

        internal static void Test()

        {

            var v2 = new Original.OxFordDefinition_perGroup { _perMainExample = new OxFordDefinition_perGroup_perMainExample_perSubExample[] { new OxFordDefinition_perGroup_perMainExample_perSubExample() } };

​

            var xml2 = v2.GetXml();

​

            Console.WriteLine(xml2);

​

            var v1 = new List.OxFordDefinition_perGroup { _perMainExample = new List<OxFordDefinition_perGroup_perMainExample_perSubExample> { new OxFordDefinition_perGroup_perMainExample_perSubExample() } };

​

            var xml1 = v1.GetXml();

​

            Console.WriteLine(xml1);

        }

    }

    public class Program

    {

        public static void Main()

        {

            TestClass.Test();

        }

    }

​

    public static class XmlSerializationHelper

    {

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

        {

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

            T returnValue = default(T);

            using (StringReader reader = new StringReader(xmlString))

            {

                object result = serial.Deserialize(reader);

                if (result is T)

                {

                    returnValue = (T)result;

                }

            }

            return returnValue;

        }

​

        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();

            }

        }

    }

}

​