using System;

using System.Collections.Generic;

using AutoMapper;

using Newtonsoft.Json;

​

public class Program

{

    public static void Main()

    {

        var config = new MapperConfiguration(cfg =>

        {       

            cfg.CreateMap<Trip, Route>()

                .ForMember(dest => dest.SequNumber, o => o.MapFrom(src => src.TrainNumber));

            cfg.AllowNullDestinationValues = true;

            cfg.CreateMap<ReservationSource, ReservationDestination>()

                .ForMember(dest => dest.SeqNumber, o => o.MapFrom(src => src.SeqNo))

                .ForPath(dest => dest.TravelDest, o => o.MapFrom(src => src.TravelSource.Trips));

        });

        IMapper mapper = config.CreateMapper();

        var source = new ReservationSource

        {

            SeqNo = "Seq001",

            TravelSource = new Travel

            {

                TravelId = "1",

                Trips = new List<Trip>

                {

                    new Trip { TrainNumber = "A0001" },

                    new Trip { TrainNumber = "B0001" }

                }

            }

        };

        var destination = mapper.Map<ReservationSource, ReservationDestination>(source);

        Console.WriteLine(JsonConvert.SerializeObject(destination));

    }

}

​

public class ReservationSource

{

    public Travel TravelSource { get; set; }

​

    public string SeqNo { get; set; }

}

​

public class Travel

{

    public string TravelId { get; set; }

​

    public ICollection<Trip> Trips { get; set; }

}

​

public class Trip

{

    public string TrainNumber { get; set; }

​

    public string Arrival { get; set; }

}

​

public class ReservationDestination

{

    public Route[] TravelDest { get; set; }

​

    public string SeqNumber { get; set; }

}

​

public class Route

{

    public string SequNumber { get; set; }

​

    public string RouteId { get; set; }

}