using System;

using Newtonsoft.Json.Linq;

using Newtonsoft.Json;

using System.Xml;

using System.Xml.Linq;

​

public class Program

{

    public static void Main()

    {

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

  <root>

   <foo>bar</foo>

 </root>";

        var xml = XElement.Parse(renderedOutput);

        var xmlWithoutRoot = JsonConvert.SerializeXNode(xml, Newtonsoft.Json.Formatting.None, true);

        // convert XML to JSON

        var newJson = JsonConvert.SerializeObject(xmlWithoutRoot);

        Console.WriteLine(newJson);

    }

}