具有 Entity Framework 的 C# AutoMapper - 适用于 List 但不适用于单个可空实例

Question

我有一个非常奇怪的错误，我无法理解。我将 AutoMapper 6 与 AutoMapper.Collection 和 AutoMapper.Collection.EntityFramework 一起使用。

https://github.com/AutoMapper/AutoMapper.Collection

正如您从下面的屏幕截图中看到的，除了 updatedContact 为 null 的图像之外，每个组件都已更新。但是，如果我只对 updatedImage 进行显式映射，它就可以工作。它还可以毫无问题地更新图像集合。有没有人经历过这个？其他单个属性也适用，但由于某些原因 Image 造成了麻烦。

//Works
var updatedArticle = Mapper.Map<ArticleViewModel, Article>(articleVm, articleOriginal);
//Every component is updated a part from Image.
var updatedContact = Mapper.Map<ContactViewModel, Contact>(contactVm, contactOriginal);
//Works
var updatedImage = Mapper.Map<ImageViewModel, Image>(contactVm.Image);
//Works
var newContact = Mapper.Map<ContactViewModel, Contact>(contactVm);

映射：

cfg.CreateMap<ArticleViewModel, Article>(MemberList.Source)
    .EqualityComparison((src, dst) => src.Id == dst.Id);

cfg.CreateMap<ImageViewModel, Image>(MemberList.Source)
    .EqualityComparison((src, dst) => src.Id == dst.Id)
    .ForSourceMember(x => x.IsDeleted, opt => opt.Ignore())
    .ForMember(dest => dest.ImageBytes, opt => opt.MapFrom(src => Encoding.ASCII.GetBytes(src.Image)));

cfg.CreateMap<ContactViewModel, Contact>(MemberList.Source)
.EqualityComparison((src, dst) => src.Id == dst.Id)
.ForSourceMember(x => x.IsDeleted, opt => opt.Ignore())
.ForSourceMember(x => x.FullName, opt => opt.Ignore());

文件：

public class ArticleViewModel
{
    public int Id { get; set; }
    ... 
    public List<ImageViewModel> Images { get; set; }
}

public class Article : IEntity<int>
{
    public int Id { get; set; }
    ...
    public virtual ICollection<Image> Images { get; set; }  
}

public class ContactViewModel
{
    public int Id { get; set; }
    ... 
    public ImageViewModel Image { get; set; }
}

public class Contact: IEntity<int>
{
    [Key]
    public int Id { get; set; }

    ...

    public int? ImageId { get; set; }

    public Image Image { get; set; }

}

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

    public string Image { get; set; }

    public string ImageType { get; set; }

    public bool IsDeleted { get; set; }
}

public class Image : IEntity<int>
{
    [Key, DatabaseGenerated(DatabaseGeneratedOption.Identity)]
    public int Id { get; set; }

    public DateTime Created { get; set; }

    public DateTime Updated { get; set; }

    public byte[] ImageBytes { get; set; }

    public string ImageType { get; set; }

    public int? ArticleId { get; set; }

    public virtual Article Article { get; set; }
}

Answer 1

我认为您需要在配置中告诉您的联系人映射器明确使用映像虚拟机的映射。可能会有一两个错别字，因为我是凭记忆做的，但它应该类似于：

.ForMember(x => x.Image, opt => opt.MapFrom(contact => Mapper.Map<ImageViewModel, Image>(contact.ImageVm);))

Answer 2

终于解决了，我忘记在Contact中将Image标记为virtual。这样做之后，一切都开箱即用。

public virtual Image Image { get; set; }

具有 Entity Framework 的 C# AutoMapper - 适用于 List 但不适用于单个可空实例

C# AutoMapper with Entity Framework - Works with List but not single nullable instance

c#

entity-framework

automapper

automapper-6