Automapper 从一个对象映射到嵌套对象

Question

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);
        }
    }

Answer 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));

Answer 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>>());

Answer 3

ResolveUsing is not available with latest version of AutoMapper. So only option left is to use MapFrom . (use @ZedRoth solution).