Automapper 9：map 子属性

Question

With Automapper 7 i use this code to map child property:

    Mapper.CreateMap<DomainClass, Child>();
    Mapper.CreateMap<DomainClass, Parent>()
      .ForMember(d => d.Id, opt => opt.MapFrom(s => s.Id))
      .ForMember(d => d.A, opt => opt.MapFrom(s => s.A))
      .ForMember(d => d.Child, 
                 opt => opt.MapFrom(s => Mapper.Map<DomainClass, Child>(s)))

Now, with Automapper 9 I cannot use the static Mapper object
I use DI to inject th mapper object in MappingProfile class

        private readonly IMapper _mapper;

        public MappingProfile(IMapper mapper)
        {
            _mapper = mapper;
        }

Then I use the _mapper object instead of the static Mapper

 Mapper.CreateMap<DomainClass, Child>();
 Mapper.CreateMap<DomainClass, Parent>()
   .ForMember(d => d.Id, opt => opt.MapFrom(s => s.Id))
   .ForMember(d => d.A, opt => opt.MapFrom(s => s.A))
   .ForMember(d => d.Child, 
              opt => opt.MapFrom(s => _mapper.Map<DomainClass, Child>(s)))

But it doesn't work. The Child property is always null. What am I doing wrong?

Answer 1

You can try something like that

 static Mapper InitializeAutomapper()
    {
        var config = new MapperConfiguration(cfg => {
            cfg.CreateMap<DomainClass, Child>();
        });
        var mapper = new Mapper(config);
        return mapper;
    }
 var mapper = InitializeAutomapper();
Mapper.CreateMap<DomainClass, Child>();
Mapper.CreateMap<DomainClass, Parent>()
.ForMember(d => d.Id, opt => opt.MapFrom(s => s.Id))
.ForMember(d => d.A, opt => opt.MapFrom(s => s.A))
.ForMember(d => d.Child, 
              opt => opt.MapFrom(s => mapper.Map<DomainClass, Child>(s)))