Getting Automapper error when trying to map nested objects

问题

I have a Box object which has a list of SerialNumber objects nested within it. I'm trying to map the SerialNumberName property of each SerialNumber in each Box to a model called BoxedElectrodesModel.

Here is my Box class and its nested SerialNumber class:

public partial class Box
{
    [System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Usage", "CA2214:DoNotCallOverridableMethodsInConstructors")]
    public Box()
    {
        this.SerialNumbers = new HashSet<SerialNumber>();
    }

    public int BoxID { get; set; }
    public System.DateTime DateCreated { get; set; }
    public Nullable<System.DateTime> DateShipped { get; set; }
    public string TrackingNumber { get; set; }
    public Nullable<System.DateTime> DateReceived { get; set; }
    public bool Active { get; set; }

    [System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Usage", "CA2227:CollectionPropertiesShouldBeReadOnly")]
    public virtual ICollection<SerialNumber> SerialNumbers { get; set; }
}

public partial class SerialNumber
{
    [System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Usage", "CA2214:DoNotCallOverridableMethodsInConstructors")]
    public SerialNumber()
    {
        this.Comments = new HashSet<Comment>();
        this.WIPHistories = new HashSet<WIPHistory>();
    }

    public int SerialNumberID { get; set; }
    public int IncomingLotID { get; set; }
    public string SerialNumber1 { get; set; }
    public string LamPurchaseOrder { get; set; }
    public string LamLineNumber { get; set; }
    public bool Refurbished { get; set; }
    public int WIPLocationID { get; set; }
    public int StatusID { get; set; }
    public int RouteSectionStepID { get; set; }
    public Nullable<int> RejectCategoryID { get; set; }
    public Nullable<int> BoxID { get; set; }

    [System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Usage", "CA2227:CollectionPropertiesShouldBeReadOnly")]
    public virtual ICollection<Comment> Comments { get; set; }
    public virtual IncomingLot IncomingLot { get; set; }
    public virtual RejectCategory RejectCategory { get; set; }
    public virtual Status Status { get; set; }
    public virtual WIPLocation WIPLocation { get; set; }
    [System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Usage", "CA2227:CollectionPropertiesShouldBeReadOnly")]
    public virtual ICollection<WIPHistory> WIPHistories { get; set; }
    public virtual Box Box { get; set; }
    public virtual RouteSectionStep RouteSectionStep { get; set; }
}

...and here is my 'BoxedElectrodesRowModel' class and its nested SerialNumberModel class:

public class BoxedElectrodesRowModel
{
    public int BoxId { get; set; }
    public List<SerialNumberModel> SerialNumbers { get; set; }
    public Nullable<System.DateTime> DateCreated { get; set; }
}

public class SerialNumberModel
{
    public string Name { get; set; }
}

Here's my AutoMapper code:

            c.CreateMap<Box, BoxedElectrodesRowModel>()
                .ForMember(dest => dest.BoxId, opts => opts.MapFrom(src => src.BoxID))
                .ForMember(dest => dest.SerialNumbers.Select(sn => sn.Name), opts => opts.MapFrom(src => src.SerialNumbers.Select(t => t.SerialNumberName)))
                .ForMember(dest => dest.DateCreated, opts => opts.MapFrom(src => src.DateCreated));

And here is my error message:

"Custom configuration for members is only supported for top-level individual members on a type."

The problem, I think, has something to do with the fact that I'm trying to map the nested property SerialNumberName from Box > SerialNumbers to the nested property Name from BoxedElectrodesRowModel > SerialNumbers.

How do I go about fixing this?

回答1:

Try to map the the items SerialNumber and SerialNumberModel firstly and then AutoMapper will use that mapping when it is mapping from one list to another.

Mapper.Initialize( cfg =>
{
   cfg.CreateMap<SerialNumber, SerialNumberModel>()
      .ForMember( dest => dest.Name, opts => opts.MapFrom(src => src.SerialNumberName));
   cfg.CreateMap<Box, BoxedElectrodesRowModel>()
      .ForMember( dest => dest.BoxId, opts => opts.MapFrom( src => src.BoxID ) )
      .ForMember( dest => dest.DateCreated, opts => opts.MapFrom( src => src.DateCreated ) );
} );

来源：https://stackoverflow.com/questions/41753827/getting-automapper-error-when-trying-to-map-nested-objects