c# - 从 ViewModel 映射回 DTO 时出现 AutoMapper 问题

Question

我在映射回 DTO 时遇到问题。

DTO:

public class ServiceEntity : BaseChild
{
    public int Id { get; set; }
}

public class BaseChild
{
    public string FirstName { get; set; }
    public string LastName { get; set; }
    public int Salary { get; set; }
    public string BkName { get; set; }
    public int BkPrice { get; set; }
    public string BkDescription { get; set; }
}

View 模型:

public class BusinessEntity 
{
    public ChildBussiness Details { get; set; }
}

public class ChildBussiness
{
    public string NameFirst { get; set; }
    public string LastName { get; set; }
    public Books BookDetails { get; set; }
    public string Salary { get; set; }
}

public class Books
{
    public string BookName { get; set; }
    public int BookPrice { get; set; }
    public string BookDescription { get; set; }
}

Controller

对于从 DTO 到 ViewModel 的映射，我使用以下代码，它工作正常。

public ActionResult Index()
{
    ServiceEntity obj = GetData();
    Mapper.CreateMap<ServiceEntity, BusinessEntity>()
        .ForMember(d => d.Details, o => o.MapFrom(x => new ChildBussiness { NameFirst = x.FirstName, LastName = x.LastName, Salary = x.Salary.ToString(), BookDetails = new Books { BookDescription = x.BkDescription, BookName = x.BkName, BookPrice = x.BkPrice }}));

    BusinessEntity objDetails = Mapper.Map<ServiceEntity, BusinessEntity>(obj);
}

虽然转换回来我做不到。下面是我试过的代码。

.
.
.
ServiceEntity objser = new ServiceEntity();

Mapper.CreateMap<BusinessEntity, ServiceEntity>();
Mapper.CreateMap<Books, ServiceEntity>();

objser = Mapper.Map<BusinessEntity, ServiceEntity>(model);
.
.
.

但我没有取得任何成功。例如，我提供了一些属性。我实时我可能拥有超过 30 个属性(property)。任何建议将不胜感激...

Answer 1

编辑 因此，您可以更改 BusinessEntity 实现，您可以使用 AutoMapper 约定和扁平化的强大功能。这是修改后的业务实体:

public class BusinessEntity
{
    public string FirstName { get; set; } // Instead of NameFirst
    public string LastName { get; set; }
    public Book Bk { get; set; } // Bk instead of BookDetails
    public string Salary { get; set; }
}

public class Book
{
    public string Name { get; set; } // No prefixes
    public int Price { get; set; }
    public string Description { get; set; }
}

您需要 Bk 名称以允许将 Bk.Name 扁平化为 BkName。现在所有映射都将在几行中生成:

// For mapping from service entity to book
Mapper.Initialize(cfg => cfg.RecognizePrefixes("Bk"));

Mapper.CreateMap<BusinessEntity, ServiceEntity>();

// Trick to un-flatten service entity
// It is mapped both to Book and BusinessEnity
Mapper.CreateMap<ServiceEntity, Book>();
Mapper.CreateMap<ServiceEntity, BusinessEntity>()
        .ForMember(d => d.Bk, m => m.MapFrom(s => s));

就是这样。所有 30 个属性都将按照约定进行映射:

var service = new ServiceEntity {
    FirstName = "Sergey",
    LastName = "Berezovskiy",
    Salary = 5000,
    BkName = "Laziness in Action",
    BkDescription = "...",
    BkPrice = 42
};

var business = Mapper.Map<BusinessEntity>(source);
var anotherService = Mapper.Map<ServiceEntity>(business);

原始答案 因此您正在使用自定义映射，从服务实体到业务实体，那么默认映射也不适用于向后映射。您应该手动为成员提供映射:

Mapper.CreateMap<BusinessEntity, ServiceEntity>()
    .ForMember(d => d.FirstName, m => m.MapFrom(s => s.Details.NameFirst))
    .ForMember(d => d.LastName, m => m.MapFrom(s => s.Details.LastName))
    .ForMember(d => d.Salary, m => m.MapFrom(s => s.Details.Salary))
    .ForMember(d => d.BkName, m => m.MapFrom(s => s.Details.BookDetails.BookName))
    .ForMember(d => d.BkPrice, m => m.MapFrom(s => s.Details.BookDetails.BookPrice))
    .ForMember(d => d.BkDescription, m => m.MapFrom(s => s.Details.BookDetails.BookDescription));

但我认为在这种情况下手动映射更好，然后为各个属性提供所有这些映射。