AutoMapper ConstructServicesUsing is ignored - automapper

Question

I have a Person and a PersonViewModel. I created a map from Person => PersonViewModel. The problem is that PersonViewModel's only constructor needs an argument (it has a dependency that I want to be injected) and AutoMapper is complaining because it says it needs a parameterless constructor.
To fix it, I used the ConstructServicesUsing method, but I haven't been successful with it :(
To illustrate the case, I created a test for you to see what I'm doing. It's pretty simple:
[TestMethod]
public void TestConstructServicesUsing()
{
Mapper.Initialize(configuration =>
{
configuration.ConstructServicesUsing(FactoryMethod);
configuration.CreateMap<Person, PersonViewModel>();
});
Mapper.AssertConfigurationIsValid();
var person = new Person();
var personViewModel = Mapper.Map<Person, PersonViewModel>(person);
}
private object FactoryMethod(Type type)
{
throw new NotImplementedException();
}
}
The rest of the code is the classes and interface definitions. They are almost empty.
public class SomeyDependency : ISomeDependency
{
}
public class PersonViewModel
{
private readonly ISomeDependency service;
public PersonViewModel(ISomeDependency service)
{
this.service = service;
}
public string Name { get; set; }
}
public class Person
{
public string Name { get; set; }
}
public interface ISomeDependency
{
}
As you see, I provide AutoMapper with a FactoryMethod, but it never get called.
When it reaches the last line of the test (Mapper.Map<...>()) it throws an excepton saying:
AutoMapper.AutoMapperMappingException:
Mapping types:
Person -> PersonViewModel
MappingWithContainerTests.Person -> MappingWithContainerTests.PersonViewModel
Destination path:
PersonViewModel
Source value:
MappingWithContainerTests.Person ---> System.ArgumentException: Type needs to have a constructor with 0 args or only optional args
Parameter name: type
What's the problem?
Why isn't the FactoryMethod being called?

Answer 1

As #khorvat mention where is missing .ConstructUsingServiceLocator(), for concrete mapping.
Also you can set constructor directly by
.ConstructUsing(source => Method(source.anySourceOptions))
Or as exception said:
PersonViewModel, must have a constructor with 0 args or only optional
args. You have only one constructor with 1 not optional argument
you may create one more constructor without args:
public PersonViewModel()
{
this.service = new SomeDependency();
}

Answer 2

I'm using .NET Core 3.1 and Automapper.Extensions.Microsoft.DependencyInjection.
This does not work for me (Same error as yours):
public class AutoMapping : Profile
{
public AutoMapping()
{
CreateMap<Context, MainViewModel>()
.ReverseMap()
.ConstructUsingServiceLocator();
}
}
But this does work:
public class AutoMapping : Profile
{
public AutoMapping()
{
CreateMap<Context, MainViewModel>()
.ConstructUsingServiceLocator()
.ReverseMap();
}
}
I still do not fully understand the cause.