我有这样的源和目标对象:
class ProductWithCategories // Source class
{
public Product Product { get; set; } // Product is an EF entity class
public IEnumerable<Category> Categories { get; set; }
}
class ProductViewModel // Dest class
{
public int Id { get; set; }
// Other properties with the same name as Product class
public IEnumerable<CategoryViewModel> Categories { get; set; }
}
因此,我需要将source.Product
的值映射到dest
,然后将source.Categories
映射到dest.Categories
。是否可以使用AutoMapper?
我尝试了这一点,当它失败时我并不感到惊讶:
config.CreateMap<ProductWithCategories, ProductViewModel>()
.ForMember(q => q, option => option.MapFrom(q => q.Product))
.ForMember(q => q.Categories, option => option.MapFrom(q => q.Categories));
以下是我收到的例外情况:
[AutoMapperConfigurationException:成员的自定义配置是 仅支持类型上的顶级个人成员。]
答案 0 :(得分:24)
在与OP讨论之后,事实证明他的主要需求是将源对象内的子/嵌套对象快速映射到展平的目标对象。他不想为目的地的每个属性写一个映射。
以下是实现此目的的方法:
Product
- &gt; ProductViewModel
用于展平产品Category
定义为CategoryViewModel
定义映射ProductWithCategories
- &gt; ProductViewModel
映射类别,然后在aftermap中映射Product
:
config.CreateMap<ProductWithCategories, ProductViewModel>()
.ForMember(q => q.Id, option => option.Ignore()) // flattened in AfterMap
.ForMember(q => q.Categories, option => option.MapFrom(q => q.Categories))
.AfterMap((src, dst) => Mapper.Map(src.Product, dst));
答案 1 :(得分:8)
使用最新版本的AutoMapper,您可以执行以下操作:
config.CreateMap<Product, ProductViewModel>()
.ForMember(q => q.Categories, option => option.Ignore());
config.CreateMap<ProductWithCategories, ProductViewModel>()
.ConstructUsing(s => AutoMapper.Mapper.Map<ProductViewModel>(s.Product))
.ForMember(q => q.Categories, option => option.MapFrom(q => q.Categories))
.ForAllOtherMembers(o => o.Ignore();
ConstructUsing()用于从源的嵌套子[ren]生成和填充基类。如果您有多个这样的嵌套子级,则需要进行多次映射调用,将其中的每一个连续映射到第一次Map()调用生成的实例上。 .ForAllOtherMembers()是相对较新的(如果您没有它,请获取更新版本的AutoMapper。)不幸的是,它稍微不安全,就好像您添加了需要映射但忘记更新地图的目标成员,配置验证不会抓住它。
答案 2 :(得分:0)
你应该这样做 -
AutoMapper.Mapper.CreateMap<Category, CategoryViewModel>();
AutoMapper.Mapper.CreateMap<ProductWithCategories, ProductViewModel>()
.ForMember(a => a.Id, b => b.ResolveUsing(c => c.Product != null ? c.Product.MyProperty : 0))
.ForMember(a => a.Categories, b => b.ResolveUsing(c => c.Categories));
但最好将ProductViewModel
(类似Id
之类的道具)中的属性包装在另一个类中。并创建另一个地图,让事物以自动播放方式工作。
答案 3 :(得分:-1)
产生错误的违规行是
.ForMember(q => q.Id, option => option.MapFrom(q => q.Product.Id))
.ForMember(q => q.OtherProperty, option => option.MapFrom(q => q.Product.OtherProperty))
错误消息很难理解,但这意味着您必须明确说明目标属性:
Category
您还需要定义从CategoryViewModel
到.ForMember(q => q.Categories, option => option.MapFrom(q => q.Categories))
的映射
config.CreateMap<Category, CategoryViewModel>();
工作:
var unitOfWorkProvider = new PetaPocoUnitOfWorkProvider();
using (var uow = unitOfWorkProvider.GetUnitOfWork("SomeConnectionString"))
{
var errorNumber = new SqlParameter("@ErrorNumber", SqlDbType.Int) { Direction = ParameterDirection.Output };
var errorSeverity = new SqlParameter("@ErrorSeverity", SqlDbType.Int) { Direction = ParameterDirection.Output };
var errorState = new SqlParameter("@ErrorState", SqlDbType.Int) { Direction = ParameterDirection.Output };
var errorProcedure = new SqlParameter("@ErrorProcedure", SqlDbType.NVarChar) { Direction = ParameterDirection.Output, Size = 128 };
var errorLine = new SqlParameter("@ErrorLine", SqlDbType.Int) { Direction = ParameterDirection.Output };
var errorMessage = new SqlParameter("@ErrorMessage", SqlDbType.NVarChar) { Direction = ParameterDirection.Output, Size = 4000 };
var sqlScript = Sql.Builder.Append(";EXEC @0 " +
" @@Uid = @1," +
" @@ErrorNumber = @2 OUTPUT," +
" @@ErrorSeverity = @3 OUTPUT," +
" @@ErrorState = @4 OUTPUT," +
" @@ErrorProcedure = @5 OUTPUT," +
" @@ErrorLine = @6 OUTPUT," +
" @@ErrorMessage = @7 OUTPUT",
"[Schema].[USP_BlaDiBla]",
new Guid("1E454A42-CC41-4FA1-BE91-1F7689986A23").ToString(),
errorNumber,
errorSeverity,
errorState,
errorProcedure,
errorLine,
errorMessage
);
var result = UnitOfWork.Current.FirstOrDefault<SomeDto>(sqlScript);
}