Automapper does not work for Lists?

Question

I have two classes, Sale and SaleDTO.

When I map objects of these two classes using automapper, it will work.

However, if I do something like this:

List<Sale> s = GetSalesFromDatabaseMethod();
List<SaleDTO> sa = Mapping.Map<List<Sale>, List<SaleDTO>>(s);

sa will turn up empty. Am I doing something wrong?

The Map method is basically a shortcut to mapping:

public static H Map<T, H>(T i) {
    Mapper.CreateMap<T, H>();
    return Mapper.Map<T, H>(i);
}

Answer 1

I found the answer from Automapper copy List to List.

Apparently the shortcut Mapping.Map<>() that I made method would not work, as I need to create the map to the two classes first and then map the lists, like so:

Mapper.CreateMap<Sale, SaleDTO>();
List<SaleDTO> sa = Mapper.Map<List<Sale>, List<SaleDTO>>(s);