Automapper map from one object to nested objects

问题:

What is the best way to map inner objects with Automapper 2.0

1. Use the solution in this question (Automapper 1.0)

2. Create a Custom Value Resolvers

3. ?

   public class DTOObject
   {
       // MainObject
       public int Id { get; set; }
       public string Name { get; set; }
   
       // SubObject (TopObject)
       public string TopText { get; set; }
       public string TopFont { get; set; }
   
       // SubObject (BottomObject)
       public string BottomText { get; set; }
       public string BottomFont { get; set; }
   }
   
   public class MainObject
   {
       public int Id { get; set; }
       public string Name { get; set; }
   
       public SubObject TopObject { get; set; }
       public SubObject BottomObject { get; set; }
   }
   
   public class SubObject
   {
       public string SubPropText { get; set; }
       public string SubPropFont { get; set; }
   }
   

Custom Value Resolvers

    public class CustomResolver : ValueResolver<DTOObject, SubObject>
    {
        protected override SubObject ResolveCore(DTOObject source)
        {
            return Mapper.Map<DTOObject, SubObject>(source);
        }
    }

回答1:

For me it was possible to use just MapFrom (without ResolveUsing what gives you a chance to use this mapping with IQueryable extensions). So you will get the following in the Automapper configuration:

Mapper.CreateMap<DTOObject, SubObject>()
    .ForMember(dest => dest.SubPropText, opt => opt.MapFrom(x => x.BottomText))
    .ForMember(dest => dest.SubPropFont, opt => opt.MapFrom(x => x.BottomFont));

Mapper.CreateMap<DTOObject, MainObject>()
    .ForMember(dest => dest.SubPart, opt => opt.MapFrom(x => x));

回答2:

I ended up creating my own value resolvers for any SubObjects of MainObject that come from DTOObject.

public class PartResolver<T> : ValueResolver<DTOObject, T>
{
    protected override T ResolveCore(DTOObject source)
    {
        return Mapper.Map<T>(source);
    }
}

Then in my Automapper config I create a map from the DTOObject to SubObject and use the ValueResolver to map that object into the MainObject

Mapper.CreateMap<DTOObject, SubObject>();

Mapper.CreateMap<DTOObject, MainObject>()
    .ForMember(dest => dest.SubPart, opt => opt.ResolveUsing<PartResolver<SubObject>>());