c# - AutoMapper: how to use Explicit Expansion inside IMapper.Map()

Question

Is there any way to use IMapper.Map like this:

IMapper mapper = new Mapper(config);

MemberDTO dto = mapper.Map<Member, MemberDTO>(member, config, m => m.Membership); // this is not supported

which works similarly to ProjectTo ?:

Member dto = db.Members.Where(m => m.Id = id).ProjectTo<MemberDTO>(config, m => m.Membership).FirstOrDefault();

The problem is that in my ASP.NET MVC app, I need to update an entity then return its DTO

public MemberDTO Update(int id)
{
    // First get the member Id in database
    Member member = _db.Members.FirstOrDefault(m => m.Id == id);
    
    // Do many many update stuffs
    ....
    _db.SaveChanges();
    
    // Map to DTO
    MemberDTO dto = _mapper.Map<Member, MemberDTO>(member);

    return dto;
}

I use EF lazy loading and IMapper.Map returns unneccessary navigation properties and results in a reference loop. I want to use specify what navigation to map inside this, as specified in the mapping config:

CreateMap<Membero, MemberDTO>()
   .ForMember(x => x.Membership, opt => opt.ExplicitExpansion())
   .....

What I tried:

• Using ProjectTo() but I think that I should not have another trip to the database here. I really dont want all my entity Update function to behave like that
• Detach the object from context, but then all my navigation properties are not mapped

Thanks in advance!

question from:https://stackoverflow.com/questions/65883742/automapper-how-to-use-explicit-expansion-inside-imapper-map

Answer 1

Waitting for answers