AutoMapper 不从相关实体返回对象

Question

我在 return 从相关域模型中获取对象时遇到问题。来自其他模型的对象 returning null。

我基本上想要完成的是 return 一个 DTO，它具有我想要的来自相关领域模型的字段，而不是将每个字段直接从领域模型传递到 json。

请看下面的代码，有人可以指教一下吗。

## CourseDomainModels.cs ##

public class CourseDomainModel : IObjectWithState
{
    public int Id { get; set; }
    public string Name { get; set; }
    public Double Duration { get; set; }
    public string Description { get; set; }

    public virtual TutorDomainModel CourseTutor { get; set; }
    public virtual SubjectDomainModel CourseSubject { get; set; }

    public ICollection<EnrollmentDomainModel> Enrollments { get; set; }

    [NotMapped]
    public Common.State state { get; set; }

    [NotMapped]
    public bool InDb => this.Id != default(int);

    public object PersistenceEntityId => this.Id;
}


## TutorDomainModel.cs ##

public class TutorDomainModel : IObjectWithState
{
    public int Id { get; set; }
    public string Email { get; set; }
    public string UserName { get; set; }
    public string Password { get; set; }
    public string FirstName { get; set; }
    public string LastName { get; set; }
    public Enums.Gender Gender { get; set; }

    public ICollection<CourseDomainModel> Courses;

    [NotMapped]
    public Common.State state { get; set; }

    [NotMapped]
    public bool InDb => this.Id != default(int);

    public object PersistenceEntityId => this.Id;
}

## CourseDTO.cs ##

public class CourseDTO
{
    public string Name { get; set; }

    public Double Duration { get; set; }

    public string Description { get; set; }

    public string Email { get; set; }

    public string FirstName { get; set; }

    public string LastName { get; set; }
}

## AutoMapperConfig.cs ##

public class AutoMapperConfig
{
    public static void RegisterMapping()
    {

        Mapper.CreateMap<CourseDomainModel, CourseDTO>();
    }
}

## Startup.cs ##

public class Startup
{
    public void Configuration(IAppBuilder app)
    {
        HttpConfiguration config = new HttpConfiguration();
        WebApiConfig.Register(config);
        app.UseWebApi(config);

        AutoMapperConfig.RegisterMapping();
    }
}

## CourseService.cs ##

public CourseDTO GetCourse(int id)
    {

        var course = _courseRepo.Get(id);
        CourseDTO courseView = Mapper.Map<CourseDomainModel,CourseDTO(course);

        return courseView;           
    }

Answer 1

AutoMapper 还不是 AI，因此您应该明确指定自定义成员映射：

Mapper.CreateMap<CourseDomainModel, CourseDTO>()
                .ForMember(dest => dest.Email, opt => opt.MapFrom(source => source.TutorDomainModel.Email));

Answer 2

AutoMapper 将 TSource 的属性映射到 TDestination 的属性，但它不会尝试从 TSource 的子属性中查找 TDestination 的属性] 默认。

您可以指示 AutoMapper 这样做：

Mapper.CreateMap<CourseDomainModel, CourseDTO>()
    .ForMember(dest => dest.Email, opt => opt.MapFrom(src => src.CourseTutor == null ? string.Empty : src.CourseTutor.Email))
    .ForMember(dest => dest.FirstName, opt => opt.MapFrom(src => src.CourseTutor == null ? string.Empty : src.CourseTutor.FirstName))
    .ForMember(dest => dest.LastName, opt => opt.MapFrom(src => src.CourseTutor == null ? string.Empty : src.CourseTutor.LastName));

CourseDTO courseView = Mapper.Map<CourseDTO>(course);

AutoMapper 不从相关实体返回对象

AutoMapper not returning objects from related entites

c#

asp.net

automapper

entity-framework-6

automapper-4