Question

Automapper能够深入查看实体导航属性以映射到DTO类吗？以下是我将实体框架查询的结果映射到DTO的过程：

          public List<ProductRequestDetailDto> GetProductRequestExtendedDetailAll()
        {      
List<ProductRequest> aProductRequestList = unitOfWork.getProductRequestRepository().GetProductRequestExtendedDetailAll();

        List<ProductRequestDetailDto> ProductRequestDetailDtoList = new List<ProductRequestDetailDto>();

        foreach (ProductRequest Req in aProductRequestList)
        {
            ProductRequestDetailDto ProdReqDetDto = new ProductRequestDetailDto();
            ProdReqDetDto.ProductRequestId = Req.ProductRequestId;
            ProdReqDetDto.FirstName = Req.Employee.FirstName;
            ProdReqDetDto.MiddleInitial = Req.Employee.MiddleInitial;
            ProdReqDetDto.LastName = Req.Employee.LastName;
            ProdReqDetDto.DeptName = Req.Employee.Department.DeptName;
            ProdReqDetDto.DeviceType = Req.ProductProfile.DeviceType;
            ProdReqDetDto.ProductName = Req.ProductProfile.ProductName;
            ProdReqDetDto.ProductId = Req.ProductProfile.ProductId;
            ProdReqDetDto.ProductRequestStageId = Req.ProductRequestStage.ProductRequestStageId;
            ProdReqDetDto.DateRequested = Req.DateRequested;
            ProdReqDetDto.DateCompleted = Req.DateCompleted;
            ProdReqDetDto.SerialNumber = Req.SerialNumber;
            ProdReqDetDto.PhoneNumber = Req.PhoneNumber;

            ProductRequestDetailDtoList.Add(ProdReqDetDto);
        }

        return ProductRequestDetailDtoList;

    public List<ProductRequest> GetProductRequestExtendedDetailAll()
    {
        var ReportResult = from Req in context.ProductRequests
                           select Req;

        return ReportResult.ToList();
    }

如果Automapper可以为我做这件事，我想避免做上述事情。当我不需要深入到导致其他实体的实体的导航属性时，Automapper已经能够将结果映射到我的DTO。我尝试了以下但是它没有用，可能是因为我需要导航到其他实体的信息，例如Employee，Department和ProductProfile：

    List<ProductRequestDetailDto> ProductRequestDetailDtoList = Mapper.Map<List<ProductRequestDetailDto>>(aProductRequestList);

如果可以做到这一点，那么正确的做法是什么？

Answer 1

您是否查看了自动映射器的扩展名Queryable Extensions，它有一个扩展名.ProjectTo可能会帮助您实现您想要实现的目标，否则您将需要为给定的案例创建映射配置。

类似

AutoMapper.Mapper.CreateMap<ProductRequestDetailDto, Req>()
    .ForMember(dest => dest.FirstName ,
               opts => opts.MapFrom(src => src.Employee.FirstName));

Answer 2

不，它无法向下钻取属性，因为它无法知道它应该有多深或者有多么模糊。

默认情况下，它只会自动映射具有相同名称的属性，因此这样可以在那里保存一些代码，但您仍需要教它如何映射其他属性。如果列表中的类型彼此映射（这将消除对foreach循环的需要），它也可以将列表映射到另一个列表。

请注意，如果具有相同名称的属性不具有相同的类型，则还需要为它们添加映射（如果它们不能相互转换）。

public List<ProductRequestDetailDto> GetProductRequestExtendedDetailAll()
{    
    AutoMapper.Mapper.CreateMap<ProductRequest, ProductRequestDetailDto>()
        .ForMember(dest => dest.FirstName, opt => opt.MapFrom(src => src.Employee.FirstName))
        .ForMember(dest => dest.MiddleInitial, opt => opt.MapFrom(src => src.Employee.MiddleInitial))
        .ForMember(dest => dest.LastName, opt => opt.MapFrom(src => src.Employee.LastName))
        .ForMember(dest => dest.DeptName, opt => opt.MapFrom(src => src.Employee.Department.DeptName))
        .ForMember(dest => dest.DeviceType, opt => opt.MapFrom(src => src.ProductProfile.DeviceType))
        .ForMember(dest => dest.ProductName, opt => opt.MapFrom(src => src.ProductProfile.ProductName))
        .ForMember(dest => dest.ProductId, opt => opt.MapFrom(src => src.ProductProfile.ProductId))
        .ForMember(dest => dest.ProductRequestStageId, opt => opt.MapFrom(src => src.ProductRequestStage.ProductRequestStageId));

    IQueryable<ProductRequest> aProductRequestList = unitOfWork.getProductRequestRepository().GetProductRequestExtendedDetailAll();

    List<ProductRequestDetailDto> ProductRequestDetailDtoList = aProductRequestList.ProjectTo<ProductRequestDetailDto>().ToList();

    // or also
    // List<ProductRequestDetailDto> ProductRequestDetailDtoList = aProductRequestList.Select(AutoMapper.Mapper.Map<ProductRequestDetailDto>).ToList();

    return ProductRequestDetailDtoList;
}

public IQueryable<ProductRequest> GetProductRequestExtendedDetailAll()
{
    var ReportResult = from Req in context.ProductRequests
                       select Req;

    return ReportResult;
}

Automapper可以使用实体的导航属性从相关实体中提取值

2 个答案: