Automapper returning an empty collection, I want a null

Question

public class Person {    Name { get; set; }    IEnumerable<Address> Addresses { get; set; } }  public class PersonModel {    Name { get; set; }    IEnumerable<AddressModel> Addresses { get; set; } } 

If I map Person to PersonModel like so:

Mapper.DynamicMap<Person, PersonModel>(person); 

If the Addresses property on Person is null they are mapped on PersonModel as an empty Enumerable instead of null.

How do I get PersonModel to have null Addresses instead of an empty Enumerable?

Answer 1

The simple answer is to use AllowNullCollections:

AutoMapper.Mapper.Initialize(cfg => {     cfg.AllowNullCollections = true; }); 

or if you use the instance API

new MapperConfiguration(cfg => {     cfg.AllowNullCollections = true; } 

Answer 2

In addition to setting AllowNullCollections in the mapper configuration initialization (as noted in this answer), you have the option to set AllowNullCollections in your Profile definition, like this:

public class MyMapper : Profile {     public MyMapper()     {         // Null collections will be mapped to null collections instead of empty collections.         AllowNullCollections = true;          CreateMap<MySource, MyDestination>();     } }