Question

我正在使用存储库模式开发.net多层应用程序。我实现存储库模式的数据访问层具有将数据返回到服务层的方法，后者又将数据返回到web api层。目前我编写的方法将返回客户信息或订单信息。我还需要编写将返回CustomerOrder信息的方法。我认为最好的地方是在服务层写它但不知道如何去做。我在服务层创建了一个DTO对象，其中包含Customer和Order类的字段。服务层是编写此逻辑的最佳位置。我想我必须填充服务层中的Dto对象并将该对象返回到表示层。有人能给我指路吗。

实体层

 public class Customers
    {


        public int Id { get; set; }
        public string FirstName { get; set; }
        public string LastName { get; set; }
        public Gender Gender { get; set; }
        public string Email { get; set; }

        public Address Address { get; set; }

        public int AddressId { get; set; }


        public ICollection<Orders> Orders { get; set; }

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

        public DateTime? OrderDate { get; set; }
        public int? OrderNumber { get; set; }

        public Customers Customers { get; set; }

        public int CustomerId { get; set; }

        public ICollection<ProductOrder> ProductOrders { get; set; }
    }

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

        public string Address1 { get; set; }

        public string Address2 { get; set; }

        public string City { get; set; }

        public State State { get; set; }

        public int StateId { get; set; }


        public ICollection<Customers> Customers { get; set; }


        public string ZipCode { get; set; }
    }

DataAccess Layer

 public class CustomerRepository : RepositoryBase<Customers>, ICustomerRepository
    {
        public CustomerRepository(IDbFactory dbFactory)
            : base(dbFactory) { }



        public IEnumerable<Customers> GetAllCustomers()
        {
            return (from customer in this.DbContext.Customers
                    select customer).ToList();
        }

    }

    public interface ICustomerRepository : IRepository<Customers>
    {
        IEnumerable<Customers> GetAllCustomers();

    }


 public class OrderRepository : RepositoryBase<Orders>, IOrderRepository
    {
        public OrderRepository(IDbFactory dbFactory)
            : base(dbFactory) {}

        public IEnumerable<Orders> GetAllOrders()
        {
            return (from order in this.DbContext.Orders
                    select order).ToList();
        }

    }

    public interface IOrderRepository : IRepository<Orders>
    {
        IEnumerable<Orders> GetAllOrders();
    }

服务层

    public interface ICustomerService
        {
            IEnumerable<Customers> GetCustomers();
        }

        public class CustomerService : ICustomerService
        {
            private readonly ICustomerRepository _customerRepository;
            private readonly IUnitOfWork _unitOfWork;

            public CustomerService(ICustomerRepository customerRepository, IUnitOfWork unitOfWork)
            {
                this._customerRepository = customerRepository;
                this._unitOfWork = unitOfWork;
            }


            public IEnumerable<Customers> GetCustomers()
            {
                return _customerRepository.GetAll();
            }




 public interface IOrderService
        {
            IEnumerable<Orders> GetOrders();

        }

        public class OrderService : IOrderService
        {
            private readonly IOrderRepository _orderRepository;
            private readonly IUnitOfWork _unitOfWork;

            public OrderService(IOrderRepository orderRepository, IUnitOfWork unitOfWork)
            {
                this._orderRepository = orderRepository;
                this._unitOfWork = unitOfWork;
            }
           }

            public IEnumerable<Orders> GetOrders()
            {
                return _orderRepository.GetAll();
            }
           }

服务层中的Dto对象

  public class CustomerDto
    {
        public int Id { get; set; }
        public string FirstName { get; set; }
        public string LastName { get; set; }
        public string Gender { get; set; }
        public string Email { get; set; }

    }



public class OrderDto
{
    public int Id { get; set; }
    public DateTime? OrderDate { get; set; }
    public int? OrderNumber { get; set; }
}
public class CustomerOrderDto
{
    public CustomerDto Customer { get; set; }
    public OrderDto Order { get; set; }

}

在服务层

中映射（域对象到Dto）

public class DomainToDtoMapping : Profile
{
    public override string ProfileName
    {
        get { return "DomainToDtoMapping"; }
    }

    [Obsolete]
    protected override void Configure()
    {
        CreateMap<Customers, CustomerDto>();
        CreateMap<Address, AddressDto>();
        CreateMap<Orders, OrderDto>();
        CreateMap<OrdersDetails, OrderDetailsDto>();
        CreateMap<State, StateDto>();


        CreateMap<CustomerDto, CustomerOrderDto>();
        CreateMap<AddressDto, CustomerOrderDto>();
        CreateMap<OrderDto, CustomerOrderDto>();
        CreateMap<OrderDetailsDto, CustomerOrderDto>();
        CreateMap<State, CustomerOrderDto>();

    }
}

Answer 1

您是否考虑过实施Composite Pattern？

您的CustomerOrderDto将包含CustomerDto和OrderDto类。像这样：

public class CustomerOrderDto
{
    public CustomerDto Customer {get; set;}
    public OrderDto Order {get; set;}
}

实施此模式将带来以下好处：

CustomerDto或OrderDto的任何未来更改都将自动成为CustomerOrderDto的一部分。
将数据映射到dto类的代码可以重复用于映射单个dto实体以及`CustomerOrderDto'。

将实体类映射到DTO类的代码应该在您的服务层中。

将Customer实体映射到CustomerDto实体：

    internal static CustomerDto Map(Customer entity)
    {
        if (entity == null) throw new ArgumentNullException("entity");

        CustomerDto dto = new CustomerDto();
        try
        {
            dto.Id = entity.Id;
            dto.FirstName = entity.FirstName;
            dto.LastName = entity.LastName;
            dto.Gender = entity.Gender;
            dto.Email = entity.Email;
        }
        catch (Exception e)
        {
            string errMsg = String.Format("Map(entity). Error mapping a Customer entity to DTO. Id: {0}.", entity.Id);
            //LOG ERROR
        }

        return dto;
    }

您是否已完成存储库层以检索Composite CustomerOrder实体？我看到您已经完成了GetAllCustomers()和GetAllOrders()的完整存储库代码。

Answer 2

试试这个：

public interface IOrderService
    {
        IEnumerable<CustomerOrderDto> GetOrders();
    }

 public IEnumerable<CustomerOrderDto> GetOrders()
    {
        List<CustomerOrderDto> customerOrderList = new List<CustomerOrderDto>();

        foreach (var item in customerOrderList)
        {
            CustomerOrderDto customerOrder = new CustomerOrderDto();
            //fields mapping

            customerOrderList.Add(customerOrder);
        }


        return customerOrderList;
    }

映射的最佳方法是linq或this.You不应该使用Automapper，因为它太慢了。

返回包含服务层中多个实体的DTO对象

2 个答案: