c# - AutoMapper convert from multiple sources

Question

Let's say I have two model classes:

public class People {
   public string FirstName {get;set;}
   public string LastName {get;set;}
}

Also have a class Phone:

public class Phone {
   public string Number {get;set;}
}

And I want to convert to a PeoplePhoneDto like this:

public class PeoplePhoneDto {
    public string FirstName {get;set;}
    public string LastName {get;set;}
    public string PhoneNumber {get;set;}
}

Let's say in my controller I have:

var people = repository.GetPeople(1);
var phone = repository.GetPhone(4);

// normally, without automapper I would made
return new PeoplePhoneDto(people, phone) ;

I cannot seem to find any example for this scenario. Is this possible ?

Note: Example is not-real, just for this question.

Answer 1

You cannot directly map many sources to single destination - you should apply maps one by one, as described in Andrew Whitaker answer. So, you have to define all mappings:

Mapper.CreateMap<People, PeoplePhoneDto>();
Mapper.CreateMap<Phone, PeoplePhoneDto>()
        .ForMember(d => d.PhoneNumber, a => a.MapFrom(s => s.Number));

Then create destination object by any of these mappings, and apply other mappings to created object. And this step can be simplified with very simple extension method:

public static TDestination Map<TSource, TDestination>(
    this TDestination destination, TSource source)
{
    return Mapper.Map(source, destination);
}

Usage is very simple:

var dto = Mapper.Map<PeoplePhoneDto>(people)
                .Map(phone);