Question

好吧我很难从模型转换到dto模型，反之亦然该模型有效，但在尝试映射AutoMapper.dll中发生“AutoMapper.AutoMapperMappingException”时

这里是模型类

public class Category
    {
        public Guid CategoryId { get; set; }

        public string CategoryName { get; set; }

        public virtual ICollection<Post> Posts { get; set; }
    }


public class Post
    {
        public Guid PostId { get; set; }

        public string PostTitle { get; set; }

        public string PostMessage { get; set; }

        public string PostImage { get; set; }

        public virtual ICollection<Tag> Tags { get; set; }

        public Guid Category_Id { get; set; }

        [ForeignKey("Category_Id")]
        public virtual Category Category { get; set; }

        public virtual IdentityUser User { get; set; }

    }

 public class Tag
    {
        public Guid TagId { get; set; }

        public string TagName { get; set; }

        public virtual List<Post> Posts { get; set; }
    }

这是我的DTO的

public class TagDto
    {
        public Guid TagId { get; set; }

        public string TagName { get; set; }

        public virtual IList<PostDto> Posts { get; set; }
    }

 public class PostDto
    {
        public Guid PostId { get; set; }


        public string PostTitle { get; set; }


        public string PostMessage { get; set; }

        public string PostImage { get; set; }

        public virtual ICollection<TagDto> Tags { get; set; }

        [Required]
        public Guid Category_Id { get; set; }

        public virtual CategoryDto Category { get; set; }

        public virtual IdentityUser User { get; set; }
    }

这就是我一直在尝试使用automapper在实体之间进行映射

public static Tag Tag_ToModel(this TagDto dto)
        {
            AutoMapper.Mapper.CreateMap<TagDto, Tag>()
                .ForMember(post => post.Posts, expr => expr.MapFrom(src => src.Posts))
                .ConstructUsing(post => AutoMapper.Mapper.Map<Tag>(post.Posts));
            var model = AutoMapper.Mapper.Map<Tag>(dto);
            return model;
        }

        public static TagDto Tag_ToDto(this Tag model)
        {
            AutoMapper.Mapper.CreateMap<Tag, TagDto>()
                .ForMember(post => post.Posts, expr => expr.MapFrom(src => src.Posts))
                .ConstructUsing(post => AutoMapper.Mapper.Map<TagDto>(post.Posts));
            var dto = AutoMapper.Mapper.Map<TagDto>(model);
            return dto;
        }

public static Post Post_ToModel(this PostDto dto)
        {
            AutoMapper.Mapper.CreateMap<PostDto, Post>()
                .ForMember(prop => prop.Comments, expr => expr.MapFrom(src => src.Comments))
                .ForMember(prop => prop.Tags, expr => expr.MapFrom(src => src.Tags))
                .ConstructUsing(category => AutoMapper.Mapper.Map<Post>(category.Category))
                .ConstructUsing(tag=>AutoMapper.Mapper.Map<Post>(tag.Tags));
            var model = AutoMapper.Mapper.Map<Post>(dto);
            return model;
        }

        public static PostDto Post_ToDto(this Post model)
        {
            AutoMapper.Mapper.CreateMap<Post, PostDto>()
                .ForMember(prop => prop.Comments, expr => expr.MapFrom(src => src.Comments))
                .ForMember(prop => prop.Tags, expr => expr.MapFrom(src => src.Tags)
                .ConstructUsing(category => AutoMapper.Mapper.Map<PostDto>(category.Category))
                .ConstructUsing(tag => AutoMapper.Mapper.Map<PostDto>(tag.Tags));
            var dto = AutoMapper.Mapper.Map<PostDto>(model);
            return dto;
        }

public static Category Category_ToModel(this CategoryDto dto)
        {
            AutoMapper.Mapper.CreateMap<CategoryDto, Category>()
                .ForMember(post => post.Posts, expr => expr.MapFrom(src => src.Posts));
            var model = AutoMapper.Mapper.Map<Category>(dto);
            return model;
        }
        public static CategoryDto Category_ToModel(this Category model)
        {
            AutoMapper.Mapper.CreateMap<Category, CategoryDto>()
                .ForMember(post => post.Posts, expr => expr.MapFrom(src => src.Posts));
            var dto = AutoMapper.Mapper.Map<CategoryDto>(model);
            return dto;
        }

我完全没有想法，也找不到任何有关如何映射此类的好教程。我认为，例如在我的类别中，“帖子”没有按照应有的方式进行映射，仍然“Post”还有其他一些导航道具，如IdentityUser，Tag，Comment和Category 而且所有这些实体都有导航道具。这种配置是我的决定，但我一直在努力尝试别人，唯一一次工作就是当我使用Ignore（）作为成员时，但这意味着将不会映射thoes道具。是否有任何具有此类问题且愿意提供帮助的自动化用户？谢谢

Answer 1

您应该在应用启动时从global.asax.cs或类似的东西调用createMap。在尝试执行任何地图操作之前，先设置所有映射一次。您需要设置所有映射，以便映射子属性，然后您不必为Posts等内容调用ForMember。

哦，摆脱构造使用。只需使用Mapper.Map。

复杂对象映射和嵌套映射

1 个答案: