using System;

using System.Collections.Generic;

using Newtonsoft.Json;

using System.Xml;

public class Program

{

    public static void Main()

    {

​

    var xml = @"<root>

  <element>

    <Id>2</Id>

    <IdParent>0</IdParent>

    <Name>4Apply-onlineOnboarding</Name>

    <ItemType>Group</ItemType>

    <children>

      <element>

        <Id>1176</Id>

        <IdParent>2</IdParent>

        <Name>TestGroup</Name>

        <ItemType>Group</ItemType>

      </element>

       <element>

        <Id>1176</Id>

        <IdParent>2</IdParent>

        <Name>TestGroup</Name>

        <ItemType>Group</ItemType>

      </element>

    </children>

  </element>

  </root>";

            XmlDocument doc = new XmlDocument();

            doc.LoadXml(xml);

​

​

​

​

    var elements = doc.GetElementsByTagName("children");

​

    if (elements.Count == 1)

    {

        var attribute = doc.CreateAttribute("json", "Array", "http://james.newtonking.com/projects/json");

        attribute.InnerText = "true";

        var node = elements.Item(0) as XmlElement;

        node.Attributes.Append(attribute);

     }

​

     string json = JsonConvert.SerializeXmlNode(doc);

​

            Console.WriteLine(json);

        //Output : {"Items":{"Item":[{"Name":"name","Detail":"detail"}]}}

    }

}

​

​