AutoMapper and inheritance - How to Map?

Question

Have this scenario:

public class Base {  public string Name; }  public Class ClassA :Base {  public int32 Number;  }  public Class ClassB :Base { public string Description;}  public Class DTO {   public string Name;   public int32 Number;   public string Description; } 

I have an IList<Base> my maps are:

AutoMapper.Mapper.CreateMap<IList<Base>, IList<DTO>>()    .ForMember(dest => dest.Number, opt => opt.Ignore())    .ForMember(dest => dest.Description, opt => opt.Ignore());  AutoMapper.Mapper.CreateMap<ClassA, DTo>()    .ForMember(dest => dest.Description, opt => opt.Ignore());  AutoMapper.Mapper.CreateMap<ClassB, DTO>()    .ForMember(dest => dest.Number, opt => opt.Ignore())  Mapper.AssertConfigurationIsValid(); //Is OK! 

But Properties that are in ClassA Or ClassB are not mapped when I do this :

IList<DTO>= AutoMapper.Mapper.Map<IList<Base>,IList<DTO>>(baseList); 

How can I do to map properties that are defined in ClasA and ClassB

Answer 1

You will need to create DTO classes that match your domain classes like this:

public class DTO {     public string Name; }  public class DTO_A : DTO {     public int Number { get; set; } }  public class DTO_B : DTO {     public string Description { get; set; } } 

You then need to change your mappings to this:

        Mapper.CreateMap<Base, DTO>()             .Include<ClassA, DTO_A>()             .Include<ClassB, DTO_B>();          Mapper.CreateMap<ClassA, DTO_A>();          Mapper.CreateMap<ClassB, DTO_B>();          Mapper.AssertConfigurationIsValid(); 

Once this is done, then the following will work:

        var baseList = new List<Base>         {             new Base {Name = "Base"},             new ClassA {Name = "ClassA", Number = 1},             new ClassB {Name = "ClassB", Description = "Desc"},         };          var test = Mapper.Map<IList<Base>,IList<DTO>>(baseList);         Console.WriteLine(test[0].Name);         Console.WriteLine(test[1].Name);         Console.WriteLine(((DTO_A)test[1]).Number);         Console.WriteLine(test[2].Name);         Console.WriteLine(((DTO_B)test[2]).Description);         Console.ReadLine(); 

Unfortunately this does mean that you have an unwanted cast, but I don't think there's much that you can do about that.