using System;

using System.Collections.Generic;

using System.Linq;

using AutoMapper;

​

namespace ConsoleApp

{

    public static class Program

    {

        private static void Main(string[] args)

        {

            var config = new MapperConfiguration(conf => conf.AddProfile<MyMapping>());

            var mapper = config.CreateMapper();

​

            var source = new StudentExamModel

            {

                StudentId = 3,

                Exams = new List<Exam>

                {

                    new Exam { Id = 1 },

                    new Exam { Id = 2 },

                    new Exam { Id = 3 },

                }

            };

​

            var dest = mapper.Map<IReadOnlyList<StudentExam>>(source);

​

            foreach (var item in dest)

            {

                Console.WriteLine($"{item.StudentId} - {item.ExamId}");

            }

        }

    }

​

    public class Exam

    {

        public int Id { get; set; }

        public string Name { get; set; }

    }

​

    public class MyMapping : Profile

    {

        public MyMapping()

        {

            CreateMap<StudentExamModel, IReadOnlyList<StudentExam>>()

                .ConvertUsing(model => model.Exams

                                    .Select(exam => new StudentExam { StudentId = exam.Id, ExamId = exam.Id.ToString() })

                                    .ToList());

        }

    }

​

    public class Student

    {

        public int Id { get; set; }

        public string Name { get; set; }

    }

​

    public class StudentExam

    {

        public string ExamId { get; set; }

        public int Id { get; set; }

        public int StudentId { get; set; }

    }

​

    public class StudentExamModel

    {

        public List<Exam> Exams { get; set; }

        public int StudentId { get; set; }

    }

}