Entity framework 将具有实体引用的实体映射到DTO cnot，并返回被引用实体的值-.NET Core，AutoMapper

最近我创建了一个实体，它与另一个实体有一对一的关系。我试图通过在API GET端点（该实体的）中使用DTO类来检索主实体的所有值和被引用实体的所有值，但收效甚微

对于其他一些实体，我创建了几个DTO类，这些类工作正常，但是这些其他实体没有我想要获取其值的引用实体

一对一（FK）关系设置如下：

主要实体：

public class Commodity
{
    public Commodity()
    {
    }

    public long CommodityID { get; set; }

    public long OMSCommodityMaterialID { get; set; }

    public decimal? SpecficWeight { get; set; }

    public virtual OmsCommodityMaterial OmsCommodityMaterial { get; set; }
}

public class OmsCommodityMaterial
{
    public OmsCommodityMaterial()
    {
    }

    public long? CommodityMaterialID { get; set; }

    public string Name { get; set; }

    public long? SortOrder { get; set; }

    [JsonIgnore]
    public virtual Commodity Commodity { get; set; }
}

public class CommodityDTO
{
    public long CommodityID { get; set; }

    public long OMSCommodityMaterialID { get; set; }

    public decimal? SpecficWeight { get; set; }

    // Referenced entity part
    public string Name { get; set; }

    public long? SortOrder { get; set; }
}

[HttpGet]
public IActionResult GetCommodities()
{
    var Commodities = this.Context.Commodity
        .Include(i => i.OmsCommodityMaterial);
    var commoditeDTO = _mapper.Map<IList<CommodityViewModel>>(Commodities);
    return Ok(commoditeDTO);
}

public class AutoMapperProfile : Profile
{
    public AutoMapperProfile()
    {
        this.CreateMap<Commodity, CommodityViewModel>();
        this.CreateMap<CommodityViewModel, Commodity>();
    }
}

引用的实体：

public class Commodity
{
    public Commodity()
    {
    }

    public long CommodityID { get; set; }

    public long OMSCommodityMaterialID { get; set; }

    public decimal? SpecficWeight { get; set; }

    public virtual OmsCommodityMaterial OmsCommodityMaterial { get; set; }
}

public class OmsCommodityMaterial
{
    public OmsCommodityMaterial()
    {
    }

    public long? CommodityMaterialID { get; set; }

    public string Name { get; set; }

    public long? SortOrder { get; set; }

    [JsonIgnore]
    public virtual Commodity Commodity { get; set; }
}

public class CommodityDTO
{
    public long CommodityID { get; set; }

    public long OMSCommodityMaterialID { get; set; }

    public decimal? SpecficWeight { get; set; }

    // Referenced entity part
    public string Name { get; set; }

    public long? SortOrder { get; set; }
}

[HttpGet]
public IActionResult GetCommodities()
{
    var Commodities = this.Context.Commodity
        .Include(i => i.OmsCommodityMaterial);
    var commoditeDTO = _mapper.Map<IList<CommodityViewModel>>(Commodities);
    return Ok(commoditeDTO);
}

public class AutoMapperProfile : Profile
{
    public AutoMapperProfile()
    {
        this.CreateMap<Commodity, CommodityViewModel>();
        this.CreateMap<CommodityViewModel, Commodity>();
    }
}

使用FLUENT API，我定义了一对一的关系：

modelBuilder.Entity<Commodity>(entity =>
{
    entity.Property(e => e.CommodityID)
        .HasColumnName("CommodityID")
        .ValueGeneratedOnAdd();

    entity.Property(e => e.OMSCommodityMaterialID)
        .HasColumnName("OMSCommodityMaterialID");

    entity.Property(e => e.SpecficWeight)
        .HasColumnName("SpecficWeight")
        .HasColumnType("decimal(18, 2)");

    entity.HasOne(a => a.OmsCommodityMaterial)
        .WithOne(b => b.Commodity)
        .HasForeignKey<Commodity>(b => b.OMSCommodityMaterialID);
});

这很好，但是我不想在端点中直接使用实体类，而且我不想使用（引用的）实体的所有字段。 在我的其他一些端点中，我使用

AutoMapper

将实体映射到DTO类/视图模型。我原以为为

GET

也这样做会相当简单，但我似乎无法让它工作

我尝试将

商品

DTO映射到我的

商品/oms商品

，如下所示：

// GET: api/commodities
[HttpGet]
public async Task<IEnumerable<Commodity>> GetCommodities()
{
    return await this.Context.Commodity
        .Include(i => i.OmsCommodityMaterial)
        .ToListAsync();
}

DTO类：

public class Commodity
{
    public Commodity()
    {
    }

    public long CommodityID { get; set; }

    public long OMSCommodityMaterialID { get; set; }

    public decimal? SpecficWeight { get; set; }

    public virtual OmsCommodityMaterial OmsCommodityMaterial { get; set; }
}

public class OmsCommodityMaterial
{
    public OmsCommodityMaterial()
    {
    }

    public long? CommodityMaterialID { get; set; }

    public string Name { get; set; }

    public long? SortOrder { get; set; }

    [JsonIgnore]
    public virtual Commodity Commodity { get; set; }
}

public class CommodityDTO
{
    public long CommodityID { get; set; }

    public long OMSCommodityMaterialID { get; set; }

    public decimal? SpecficWeight { get; set; }

    // Referenced entity part
    public string Name { get; set; }

    public long? SortOrder { get; set; }
}

[HttpGet]
public IActionResult GetCommodities()
{
    var Commodities = this.Context.Commodity
        .Include(i => i.OmsCommodityMaterial);
    var commoditeDTO = _mapper.Map<IList<CommodityViewModel>>(Commodities);
    return Ok(commoditeDTO);
}

public class AutoMapperProfile : Profile
{
    public AutoMapperProfile()
    {
        this.CreateMap<Commodity, CommodityViewModel>();
        this.CreateMap<CommodityViewModel, Commodity>();
    }
}

已调整的GET端点：

public class Commodity
{
    public Commodity()
    {
    }

    public long CommodityID { get; set; }

    public long OMSCommodityMaterialID { get; set; }

    public decimal? SpecficWeight { get; set; }

    public virtual OmsCommodityMaterial OmsCommodityMaterial { get; set; }
}

public class OmsCommodityMaterial
{
    public OmsCommodityMaterial()
    {
    }

    public long? CommodityMaterialID { get; set; }

    public string Name { get; set; }

    public long? SortOrder { get; set; }

    [JsonIgnore]
    public virtual Commodity Commodity { get; set; }
}

public class CommodityDTO
{
    public long CommodityID { get; set; }

    public long OMSCommodityMaterialID { get; set; }

    public decimal? SpecficWeight { get; set; }

    // Referenced entity part
    public string Name { get; set; }

    public long? SortOrder { get; set; }
}

[HttpGet]
public IActionResult GetCommodities()
{
    var Commodities = this.Context.Commodity
        .Include(i => i.OmsCommodityMaterial);
    var commoditeDTO = _mapper.Map<IList<CommodityViewModel>>(Commodities);
    return Ok(commoditeDTO);
}

public class AutoMapperProfile : Profile
{
    public AutoMapperProfile()
    {
        this.CreateMap<Commodity, CommodityViewModel>();
        this.CreateMap<CommodityViewModel, Commodity>();
    }
}

也许我做了一些明显的错误，但经过几次测试后，我似乎无法找到答案。也许我应该对引用的实体而不是

进行
连接
。包括

顺便说一下，我使用了以下教程作为参考：
您必须明确配置映射器，使其能够从以下位置获取映射值：

this.CreateMap<Commodity, CommodityViewModel>()
    .ForMember(dest => dest.Name, opt => opt.MapFrom(m => m.OmsCommodityMaterial.Name));

this.CreateMap（）
.ForMember（dest=>dest.Name，opt=>opt.MapFrom（m=>m.omsmoditymaterial.Name））；
您必须明确地配置映射器，使其能够从以下位置获取映射值：

this.CreateMap<Commodity, CommodityViewModel>()
    .ForMember(dest => dest.Name, opt => opt.MapFrom(m => m.OmsCommodityMaterial.Name));

this.CreateMap（）
.ForMember（dest=>dest.Name，opt=>opt.MapFrom（m=>m.omsmoditymaterial.Name））；
AutoMapper按约定映射属性。对于相关对象，该约定是在导航属性名称前加前缀。这就是AutoMapper所称的投影。例如，如果DTO属性名为
OMSComodityMaterialName
，它将自动映射
OMSComodityMaterial.Name
中的值。因为，属性只是
Name
，但是，您必须明确地告诉AutoMapper如何处理@AlexRiabov在这里建议的映射。太好了！正是我想要的。谢谢。AutoMapper按约定映射属性。对于相关对象，该约定是在导航属性名称前加前缀。这就是AutoMapper所称的投影。例如，如果DTO属性名为
OMSComodityMaterialName
，它将自动映射
OMSComodityMaterial.Name
中的值。因为，属性只是
Name
，但是，您必须明确地告诉AutoMapper如何处理@AlexRiabov在这里建议的映射。太好了！正是我想要的。非常感谢。