using System;

using System.Linq;

using System.Xml;

using System.Xml.Linq;

using Newtonsoft.Json.Linq;

public class Program

{

    public static void Main()

    {

            string xml = 

            @"<root>

                <foos>

                    <foo>

                        <id>1</id>

                        <number>1245</number>

                    </foo>

                    <foo>

                        <id>2</id>

                        <number>6743</number>

                    </foo>

                    <foo>

                        <id>3</id>

                        <number>2245</number>

                    </foo>

                </foos>

                <bars>

                    <bar>

                        <id>4</id>

                        <number>123</number>

                    </bar>

                    <bar>

                        <id>5</id>

                        <number>321</number>

                    </bar>

                </bars>

            </root>";

​

            var root = XElement.Parse(xml);

            var json = new JObject(

                root.Elements().Select(x =>

                    new JProperty(x.Name.ToString(),

                        new JArray(

                            x.Elements().Select(y =>

                                new JObject(

                                    y.Elements().Select(z =>

                                        new JProperty(z.Name.ToString(),

                                            new JValue(int.Parse(z.Value))

                                        )

                                    )

                                )

                            )

                        )

                    )

                )

            ).ToString();

​

            Console.WriteLine(json);

    }

}