entity-framework - 如何解决 AutoMapper 错误？ (stackoverflow 异常!)

Question

我正在使用 AutoMapper + EF(实体 => POCO)用于以下类:

public class Category
{
    public int CategoryID { get; set; }

    public string Name { get; set; }

    public Category Parent { get; set; }

    public IList<Category> Children { get; set; }
}

由于这个类与自身(父/子)有关系，AutoMapper 发疯了，抛出了一个 Stackoverflow 异常。你们中有人遇到过这个问题吗？

Answer 1

我已经通过创建 CustomValueResolvers 解决了它。这不是一件美丽的事情，但它正在起作用。

Mapper.CreateMap<Category, CategoryDTO>()
                .ForMember(c => c.Parent, opt => opt.ResolveUsing<ParentResolver>())
                .ForMember(c => c.Children, opt => opt.ResolveUsing<ChildrenResolver>());

Mapper.CreateMap<CategoryDTO, Category>()
                .ForMember(c => c.Parent, opt => opt.ResolveUsing<ParentDTOResolver>())
                .ForMember(c => c.Children, opt => opt.ResolveUsing<ChildrenDTOResolver>());


public class ParentResolver : ValueResolver<Category, CategoryDTO>
    {
        protected override CategoryDTO ResolveCore(Category category)
        {
            CategoryDTO dto = null;

            if (category.Parent != null)
                dto = Mapper.Map<Category, CategoryDTO>(category.Parent);

            return dto;
        }
    }

    public class ParentDTOResolver : ValueResolver<CategoryDTO, Category>
    {
        protected override Category ResolveCore(CategoryDTO category)
        {
            Category poco = null;

            if (category.Parent != null)
                poco = Mapper.Map<CategoryDTO, Category>(category.Parent);

            return poco;
        }
    }

    public class ChildrenResolver : ValueResolver<Category, EntityCollection<CategoryDTO>>
    {
        protected override EntityCollection<CategoryDTO> ResolveCore(Category category)
        {
            EntityCollection<CategoryDTO> dtos = null;

            if (category.Children != null && category.Children.Count > 0)
                dtos = Mapper.Map<IList<Category>, EntityCollection<CategoryDTO>>(category.Children);

            return dtos;
        }
    }

    public class ChildrenDTOResolver : ValueResolver<CategoryDTO, IList<Category>>
    {
        protected override IList<Category> ResolveCore(CategoryDTO category)
        {
            IList<Category> pocos = null;

            if (category.Children != null && category.Children.Count > 0)
                pocos = Mapper.Map<EntityCollection<CategoryDTO>, IList<Category>>(category.Children);

            return pocos;
        }
    }