Automapper: Flattening

Question

I've tried everything to map from Item class to ItemDto class (basically a flattening map) but I keep getting a null for ItemDto.NestedItemName:

public class Item
{
    public NestedItem NestedItem{get;set;}
}

public class NestedItem
{
    public string Name{get;set;}
}

public class ItemDto
{
    public string NestedItemName{get;set;}
}

I would have thought this would work:

CreateMap<NestedItem, ItemDto>()
                .ForMember(dest => dest.NestedItemName, opt => opt.MapFrom(src => src.Name));

but it returns null. Any ideas? I'm using AutoMapper 7.0.1 in a .Net Core 2.1 app.

Answer 1

You are using the wrong mapping. More than likely it would be the item being converted to the dto so the map should be created using that

CreateMap<Item, ItemDto>()
    .ForMember(
        dest => dest.NestedItemName, 
        opt => opt.MapFrom(src => src.NestedItem.Name)
    );

From comments

There is be no need for the custom mapping, the default naming conventions covers this