Automapper IEnumerable<t> class 的未映射</t>

Question

I use ASP.NET Core 2.2 and Automapper 9.0.0.

I have the following Order model class:

public partial class Order
{
    public Order()
    {
        OrderItems = new HashSet<OrderItem>();
    }

    public int Id { get; set; }

    public DateTime DatePlaced { get; set; }

    public virtual ICollection<OrderItem> OrderItems { get; set; }
}

and OrderDto class:

public class OrderDto
{
    public int Id { get; set; }

    public DateTime DatePlaced { get; set; }

    public IEnumerable<OrderItemsDto> Items { get; set; }

}

I've written the following configurations to map from dto to model class:

CreateMap<OrderItemsDto, OrderItem>()                
    .ForPath(dest => dest.Quantity, opt => opt.MapFrom(src => src.Quantity))
    .ForPath(dest => dest.TotalPrice, opt => opt.MapFrom(src => src.TotalPrice));


CreateMap<OrderDto, Order>()        
    .ForPath(dest => dest.DatePlaced, opt => opt.MapFrom(src => src.DatePlaced))        
    .ForPath(dest => dest.OrderItems, opt => opt.MapFrom(src => src.Items));
    // .ForMember(dest => dest.OrderItems, opt => opt.MapFrom(src => src.Items));

and this is a configuration from model to dto class:

CreateMap<OrderItem, OrderItemsDto>()
    .ForPath(dest => dest.Product.Name, opt => opt.MapFrom(src => src.Product.Name))
    .ForPath(dest => dest.Product.Price, opt => opt.MapFrom(src => src.Product.Price))
    .ForPath(dest => dest.Product.Category.Name, opt => 
        opt.MapFrom(src => src.Product.Category.Name))
    .ForPath(dest => dest.Quantity, opt => opt.MapFrom(src => src.Quantity))
    .ForPath(dest => dest.TotalPrice, opt => opt.MapFrom(src => src.TotalPrice));

CreateMap<Order, OrderDto>()
    .ForPath(dest => dest.DatePlaced, opt => opt.MapFrom(src => src.DatePlaced))
    .ForMember(dest => dest.Items, opt => opt.MapFrom(src => src.OrderItems));

However, the Items is always empty, but DatePlaced is mapped.

I've got the following result:

[
    {
        "id": 1,
        "datePlaced": "2020-02-09T21:48:13.347",      
        "items": []
    }
]

The method which returns data:

return _mapper.Map<IEnumerable<OrderDto>>(await _orderRepository.GetAll());

How can Items can me mapped correctly?

Answer 1

This is because you are missing the mapping between OrderItemsDto and OrderItem. Because of that, Automapper doesn't know how to map the items of the collection.

Adding the mappings OrderItemsDto -> OrderItem and OrderItem-> OrderItemsDto

Should fix the problem.