using System;

using System.Collections.Generic;

using System.Linq;

using AutoMapper;

​

namespace AutomapperSample

{

    public static class BlogPostDtoExtension

    {

        public static TResult MergeInto<TResult>(this IMapper mapper, object destination, object source)

        {

            return mapper.Map(source, mapper.Map<TResult>(destination));

        }

    }

    public class BlogPostProfile : Profile

    {

        public BlogPostProfile()

        {

            CreateMap<BlogPost, BlogPostResponse>();

            CreateMap<IList<Tag>, BlogPostResponse>()

                .ForMember(d => d.TagNames, 

                    a => a.MapFrom(s => string.Join(',', s.Select(x => x.Name))));

        }

    }

    class Program

    {

        static void Main(string[] args)

        {

            var blogPost = new BlogPost

            {

                Id = 1,

                Name = "Blog1",

                TagIds = new [] {1, 2}

            };

​

            var tags = new []

            {

                new Tag

                {

                    Id = 1,

                    Name = "Tag1"

                },

                new Tag

                {

                    Id = 2,

                    Name = "Tag2"

                }

            };

            var mappingConfig = new MapperConfiguration(mc =>

            {

                mc.AddProfile(new BlogPostProfile());

            });

​

            IMapper mapper = mappingConfig.CreateMapper();

            var dto = mapper.MergeInto<BlogPostResponse>(tags, blogPost);

            Console.WriteLine(dto.TagNames);

        }

    }

​

    public class BlogPostResponse

    {

        public int Id { get; set; }

        public string Name { get; set; }

        public string TagNames { get; set; }

    }

​

    public class BlogPost

    {

        public int Id { get; set; }

        public string Name { get; set; }

        public IList<int> TagIds { get; set; }

    }

​

    public class Tag

    {

        public int Id { get; set; }

        public string Name { get; set; }

    }

}

​