Automapper: Using the Structure Returned by a Custom Transformer

Question

With AutoMapper, I use a ValueResolver that returns a structure like this

struct MyStruct { public int propA; public int propB; public int propC; } class MyResolver : ValueResolver<MyViewModel, MyStruct> { protected override MyStruct ResolveCore(MyViewModel source) { ....return MyStruct data } } 

I returned the structure because the matching rules are quite complex, and I could not write a custom resolver for each property, since they are related to each other.

So my idea was to do this in one resolver that returns a structure and uses itike this

 AutoMapper.Mapper.CreateMap<MyViewModel, myData>() .ForMember(dest => dest.SomePropA, src => src.ResolveUsing<MyResolver>().propA)) .ForMember(dest => dest.SomePropB, src => src.ResolveUsing<MyResolver>().propB)) 

Unfortunately this does not work.

It looks like src.ResolveUsing<MyResolver>() does not return a structure

Any help is more than appreciated.

Thanks.

Answer 1

Using FromMember , you can pass a property from the source to your ValueResolver.

You can use something like this:

 .ForMember(dest => dest.SomePropA, opt=> opt.ResolveUsing<MyResolver>().FromMember(src => src.propA)) 

If you do not specify FromMember , AutoMapper will pass the source to your ValueResolver.