忽略Automapper中从目标到源的属性？

Question

Mapping profile:

Mapper.CreateMap<Customer, CustomerDto>();
        Mapper.CreateMap<CustomerDto, Customer>();
        Mapper.CreateMap<Movie, MoviesDto>();
        Mapper.CreateMap<MoviesDto, Movie>(MemberList.Source);

Movie class:

namespace Demo3.Models
{
    public class Movie
    {
        public int Id { get; set; }

        [Required(ErrorMessage = "Please Enter Customer Name")]
        [StringLength(255)]
        public string Name { get; set; }

        public Genre Genre { get; set; }

        [Required]
        public byte GenreId { get; set; }

        public DateTime DateAdded { get; set; }
        [Display(Name = "Release Date")]
        public DateTime ReleaseDate { get; set; }

        [Display(Name = "Number In Stock")]
        [Range(1, 20)]
        public byte NumberInStock
        {
            get; set;
        }
    }
}

MoviesDto class:

namespace Demo3.Dtos
{
    public class MoviesDto
    {
        public int Id { get; set; }

        [Required]
        [StringLength(255)]
        public string Name { get; set; }

        [Required]
        public byte GenreId { get; set; }

        public DateTime ReleaseDate { get; set; }

        //public Genre Genre { get; set; }
        [Range(1, 20)]
        public byte NumberInStock
        {
            get; set;
        }
    }
}

Exception:

An exception of type 'System.InvalidOperationException' occurred in EntityFramework.dll but was not handled in user code

and

My need is to ignore the Genre property while saving.

Answer 1

When defining the individual property mappings (which you got away without because they get mapped automagically, by having the same name), you have to specify an ignore instruction, like so:

Mapper.CreateMap<MoviesDto, Movie>()
      .ForMember(d => d.Genre, o => o.Ignore());