The AutoMapper version # is 7.0.0.
Take the following set of classes:
public class Person
{
public string Name { get; set; }
public List<BarBase> BarList { get; set; }
}
public class PersonModel
{
public string Name { get; set; }
public List<BarModelBase> BarList { get; set; }
}
abstract public class BarBase
{
public int Id { get; set; }
}
public class Bar<T> : BarBase
{
public T Value { get; set; }
}
abstract public class BarModelBase
{
public int Id { get; set; }
}
public class BarModel<T> : BarModelBase
{
public T Value { get; set; }
}
Person has a property BarList of type List<BarBase>. BarBase is an abstract class with a generic concrete implementation Bar<T>; The list needs to hold multiple types of T.
The following two configurations work. The sections commented out do not work as explained in the comments.
var config = new MapperConfiguration(cfg =>
{
cfg.CreateMap(typeof(BarBase), typeof(BarModelBase))
.Include(typeof(Bar<string>), typeof(BarModel<string>));
cfg.CreateMap(typeof(Bar<string>), typeof(BarModel<string>));
cfg.CreateMap(typeof(Person), typeof(PersonModel));
});
var config = new MapperConfiguration(cfg =>
{
//Fails with: System.NullReferenceException : Object reference not set to an instance of an object.
//cfg.CreateMap(typeof(BarBase), typeof(BarModelBase)).As(typeof(BarModel<>));
//Fails with: Missing map from AutoMapper.UnitTests.OpenGenerics+Bar`1[T] to AutoMapper.UnitTests.OpenGenerics+BarModel`1[T]. Create using Mapper.CreateMap<Bar`1, BarModel`1>.
//cfg.CreateMap(typeof(BarBase), typeof(BarModelBase))
// .Include(typeof(Bar<>), typeof(BarModel<>));
cfg.CreateMap<BarBase, BarModelBase>().ConvertUsing((source, destination, context) =>
{
System.Type sourceType = source.GetType();
System.Type structType = sourceType.GetGenericArguments()[0];
return (BarModelBase)context.Mapper.Map(source, sourceType, typeof(BarModel<>).MakeGenericType(structType));
});
cfg.CreateMap(typeof(Person), typeof(PersonModel));
cfg.CreateMap(typeof(Bar<>), typeof(BarModel<>));
});
To verify that either configuration works:
Person person = new Person
{
Name = "Jack",
BarList = new List<BarBase>
{
new Bar<string>{ Id = 1, Value = "One" },
new Bar<string>{ Id = 2, Value = "Two" }
}
};
PersonModel personMapped = config.CreateMapper().Map<PersonModel>(person);
Assert.Equal("One", ((BarModel<string>)personMapped.BarList[0]).Value);
Problem: I can't get AutoMapper's Open Generics to work for this scenario (Generic<T> extends Non-Generic) without the converter ("ConvertUsing") or by explicitly mapping each one of the closed generic types.
Question: What am I missing? - Is there an out-of-the-box type mapping configuration I can use here without using the converter?
