Automapper - Creating Maps in C#

Question

Was just getting started with AutoMapper and wanted to get clarity on something.

Let's say I want to seamlessly map between a User and a UserDto.

The examples all seem to suggest that I must first go to a startup area (for example WebApiConfig.cs or startup.cs or global.axax etc) and do something like this:

Mapper.CreateMap<User, UserDto>();

Presumably if I had 50 or 100 entities/DTOs that I wanted to map, I would need to literally add 50 or 100 lines of code with mappings between one class to another? Surely there's a smarter way, right?

If I don't ever need to do any specific mapping / overriding, do I really need to do this? I must have misunderstood the fundamentals of the framework because that just seems wrong to me.

Thanks!

Answer 1

As long as everything matches up on the source and the target, you could use DynamicMap :

var target = Mapper.DynamicMap<TSource, TTarget>(source);

However it would be more efficient to create a mapping as required:

if (Mapper.FindTypeMapFor<TSource, TTarget>() == null)
{
    Mapper.CreateMap<TSource, TTarget>();
}

var target =  Mapper.Map<TSource, TTarget>(source);