Deep level mapping using Automapper

Question

I am trying to map objects with multi-level members: these are the classes:

 public class Father     {         public int Id { get; set; }         public Son Son { get; set; }     }      public class FatherModel     {         public int Id { get; set; }         public int SonId { get; set; }     }      public class Son     {         public  int Id { get; set; }     } 

This is how I try automap it:

 AutoMapper.Mapper.CreateMap<FatherModel , Father>()                       .ForMember(dest => dest.Son.Id, opt => opt.MapFrom(src => src.SonId)); 

this is the exception that I get:

Expression 'dest => Convert(dest.Son.Id)' must resolve to top-level member and not any child object's properties. Use a custom resolver on the child type or the AfterMap option instead. Parameter name: lambdaExpression

Thanks

Answer 1

This will work both for mapping to a new or to an existing object.

Mapper.CreateMap<FatherModel, Father>()     .ForMember(x => x.Son, opt => opt.MapFrom(model => model)); Mapper.CreateMap<FatherModel, Son>()     .ForMember(x => x.Id, opt => opt.MapFrom(model => model.SonId)); 

Answer 2

    AutoMapper.Mapper.CreateMap<FatherModel, Father>()                      .ForMember(x => x.Son, opt => opt.ResolveUsing(model => new Son() {Id = model.SonId})); 

if it's getting more complex you can write a ValueResolver class, see example here- http://automapper.codeplex.com/wikipage?title=Custom%20Value%20Resolvers