using System;

public class Program

{

    public static void Main()

    {

        Otro o = new Otro();

        o.a = "vacio1";

        o.b = "vacio1";

        Motor m = new Motor();

        m.Cilindraje = 1499;

        m.Valvulas = 8;

        m.otro = o;

        Carro c = new Carro();

        c.Marca = "Chevrolet";

        c.Modelo = 2000;

        c.Puertas = 5;

        c.motor = m;

        Console.WriteLine(c.ToJson());

    }

}

​

public class Carro{

    public string Marca {get; set;}

    public int Puertas{get; set;}

    public int Modelo{get; set;}

    public Motor motor {get; set;}

    public string ToJson()

    {

        string json = "{";

        string methodName = "ToJson";

        foreach(var property in this.GetType().GetProperties()){

            if(json.Length > 1){

                json += ",";

            }

            json += property.Name + ":";

            if(property.GetValue(this, null) != null){

                var valuetmp  = property.GetValue(this, null);

                if(valuetmp.GetType().GetMethod(methodName) != null){

                    json += valuetmp.GetType().GetMethod(methodName).Invoke(valuetmp,null);

                }else{

                    json += valuetmp.ToString();

                }

            }else{

                json += "null";

            }

        }

        json += "}";

        Console.WriteLine(json);

        return json;

    }

}

​

public class Motor{

    public int Cilindraje{get; set;}

    public int Valvulas{get; set;}

    public int? Cid{get;set;}

    public Otro otro{get;set;}

    public string ToJson()

    {

        string json = "{";

        string methodName = "ToJson";

        foreach(var property in this.GetType().GetProperties()){

            if(json.Length > 1){

                json += ",";

            }

            json += property.Name + ":";

            if(property.GetValue(this, null) != null){

                var valuetmp  = property.GetValue(this, null);

                if(valuetmp.GetType().GetMethod(methodName) != null){

                    json += valuetmp.GetType().GetMethod(methodName).Invoke(valuetmp,null);

                }else{

                    json += valuetmp.ToString();

                }

            }else{

                json += "null";

            }

        }

        json += "}";

        //Console.WriteLine(json);

        return json;

    }

}

​

public class Otro{

    public string a {get; set;}

    public string b {get; set;}

    public string c {get; set;}

    public string ToJson()

    {

        string json = "{";

        string methodName = "ToJson";

        foreach(var property in this.GetType().GetProperties()){

            if(json.Length > 1){

                json += ",";

            }

            json += property.Name + ":";

            if(property.GetValue(this, null) != null){

                var valuetmp  = property.GetValue(this, null);

                if(valuetmp.GetType().GetMethod(methodName) != null){

                    json += valuetmp.GetType().GetMethod(methodName).Invoke(valuetmp,null);

                }else{

                    json += valuetmp.ToString();

                }

            }else{

                json += "null";

            }

        }

        json += "}";

        //Console.WriteLine(json);

        return json;

    }

}