C# Automapper 6.1.1 - Collection/List 目标属性丢失值 Entity Framework 6

Question

我在使用 Automapper 6 映射集合时遇到问题，我找不到解决方案。在下面的 updatedArticle 对象中，我在映射后留下了旧的 Created 和 Updated 值，因为它们在视图模型中不存在。但是，描述中 Created 和 Updated 的值丢失了。通过视图模型传入的值都已正确更新。我究竟做错了什么？ Automapper 也丢失了文章的 Entity Framework 6 个映射，因为这些值也丢失了。

控制器方法：

public async Task<IHttpActionResult> UpdateArticle(ArticleViewModel articleVm)
{
    Article articleOriginal = await iArticleRepository.GetAsync(articleVm.Id);
    Article updatedArticle = Mapper.Map<ArticleViewModel, Article>(articleVm, articleOriginal);
    return Ok();
}

映射：

Mapper.Initialize(cfg =>
{
    cfg.CreateMap<ArticleViewModel, Article>()
        .ForMember(x => x.Created, opt => opt.Ignore())
        .ForMember(x => x.Updated, opt => opt.Ignore());

    cfg.CreateMap<DescriptionViewModel, Description>()
        .ForMember(x => x.Created, opt => opt.Ignore())
        .ForMember(x => x.Updated, opt => opt.Ignore())
        .ForMember(x => x.ArticleId, opt => opt.Ignore())
        .ForMember(x => x.Article, opt => opt.Ignore());
}
Mapper.AssertConfigurationIsValid();

视图模型：

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

    public string Name { get; set; }

    public List<DescriptionViewModel> Descriptions { get; set; }
}

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

    public string Heading { get; set; }
}

型号：

public class Article : IEntity<int>
{
    public Article()
    {
        Descriptions = new List<Description>();
    }

    [Key]
    public int Id { get; set; }

    public DateTime Created { get; set; }

    public DateTime Updated { get; set; }

    [MaxLength(256)]
    public string Name { get; set; }

    public virtual ICollection<Description> Descriptions { get; set; }
}

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

    public DateTime Created { get; set; }

    public DateTime Updated { get; set; }

    [MaxLength(256)]
    public string Heading { get; set; }

    public int ArticleId { get; set; }

    public virtual Article Article { get; set; }
}

Answer 1

你试过没有延迟加载吗？我自己在使用 EF 延迟加载和 AutoMapper 时遇到了一些问题。首先效率很低。

查看相关内容 Answer.

Answer 2

折腾了两天终于解决了。从 https://github.com/AutoMapper/AutoMapper.Collection

安装 AutoMapper.Collection

PM> Install-Package AutoMapper.Collection
PM> Install-Package AutoMapper.Collection.EntityFramework

我只需要更改 cfg.AddCollectionMappers(); 和 EqualityComparison。示例：

Mapper.Initialize(cfg =>
{
    cfg.AddCollectionMappers();

    cfg.SetGeneratePropertyMaps<GenerateEntityFrameworkPrimaryKeyPropertyMaps<DbContext>>();

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

    cfg.CreateMap<DescriptionViewModel, Description>(MemberList.Source)
        .EqualityComparison((src, dst) => src.Id == dst.Id);
}
Mapper.AssertConfigurationIsValid();

C# Automapper 6.1.1 - Collection/List 目标属性丢失值 Entity Framework 6

C# Automapper 6.1.1 - Collection/List destination properties loses values Entity Framework 6

c#

entity-framework

automapper

entity-framework-6

automapper-6