使用DTO时,Automapper和Nhibernate反映了正在更新的域对象中DTO的子集合的更改

Question

我对这个设计并不熟悉,但我希望得到一些指导.

我有一个后端服务,将DTO发送到WPF智能客户端.在WPF智能客户端上,用户将更改,删除和修改项目,然后发送回更改(客户端 - >服务器).例如,目前我正在处理客户详细信息表单,用户可以在数据网格中添加,删除和更改属于客户的类别.当DTO被发送回服务器时,我想加载与DTO中的ID相关的域对象,并将对DTO所做的更改应用于域对象,包括所有子集合.

我尝试使用UpdateCustomer方法在下面的代码中执行类似的操作.但是,我认为我的观点不合时宜.当代码运行而不是最终列出{个人,公司,非政府组织,政府}时,我最终得到了{个人,B2B,公司,非政府组织,政府}的清单,因为它显然没有从中删除B2B条目原始清单.

我遇到的一个选择是遍历DTO集合并将其与域对象中的集合进行比较,并根据已修改的内容添加,删除和更新.然而,这看起来真的很麻烦.

我需要做什么才能将DTO中的更改应用到我的domiain对象中的子集合中？

非常感谢您的任何帮助,我们将非常感激

亚历克斯

    public class Customer
        {
            public virtual int Id { get; set; }
            public virtual IList<Category> Categories { get; private set; }
            public virtual string Code { get; set; }
            public virtual string Description { get; set; }

            public Customer()
            {
                Categories = new List<Category>();
            }

            public virtual void AddCategory(string categoryName)
            {
                Categories.Add(new Category(categoryName));
            }
        }

        public class Category
        {

            public virtual string CategoryName { get; private set; }
            public virtual Customer Customer {get;set;}
            public virtual int Id { get; set; }

            protected Category(){}

            public Category(string name)
            {
                CategoryName = name;
            }
        }
    }

    public void SetUpAutoMapper()
    {
        Mapper.CreateMap<Category, CategoryDto>();
        Mapper.CreateMap<Customer, CustomerDto>();
        Mapper.CreateMap<CategoryDto, Category>();
        Mapper.CreateMap<CustomerDto, Customer>();
        Mapper.AssertConfigurationIsValid();
    }
       public void SaveCustomer()
        {
            var customer = new Customer{Code="TESTCUST",Description="TEST CUSTOMER"};
             customer.AddCategory("Individual");
             customer.AddCategory("B2B");
             customer.AddCategory("Healthcare");
             customer.AddCategory("NGO");
             repository.Save(customer);
        }

     public CustomerDto GetCustomer(int customerId)
     { 
        var customer = repository.GetCustomer(customerId);
        var customerDto = Mapper.Map<Customer,CustomerDto>(customer);
        return customerDto;
     }

    public void UpateCustomer(CustomerDto customerToUpdate)
    {
        /*imagine that the dto incoming has had the following operations performed on it
        -----add new category----
        customerToUpdate.Categories.Add(new CategoryDto {CategoryName = "Government"});
        ---update existing category---
        customerToUpdate.Categories[2].CategoryName = "Company";
        ---remove category---
        customerToUpdate.Categories.RemoveAt(1);*/

        var customer = repository.GetCustomer(customerToUpdate.Id);
        /* How in this bit do I ensure that the child collection changes are
        propogated into the underlying customer object retrieved from the database*/
        var customer = Mapper.Map<CustomerDto,Customer>(customerToUpdate);
        repository.Save(customer);
    }

public class CustomerDto
    {
        public int Id { get; set; }
        public string Code { get; set; }
        public string Description { get; set; }
        public List<CategoryDto> Categories { get; set; }
    }

    public class CategoryDto
    {
        public int Id { get; set; }
        public string CategoryName { get; set; }
    }

    <hibernate-mapping xmlns="urn:nhibernate-mapping-2.2">
      <class name="Customer" table="Customer">
        <id name="Id" column="CustomerId">
          <generator class="native"/>
        </id>
        <property name="Code" />
        <property name="Description" />
        <bag name="Categories" table="Categories" cascade="all" inverse="false">
          <key column="FK_CustomerID" />
          <one-to-many class="Category"/>
        </bag>
      </class>

      <class name="Category" table="Categories">
        <id name="Id" column="CategoryId">
          <generator class="native"/>
        </id>
        <many-to-one name="Customer" column="FK_CustomerId" not-null="true" class="Customer"></many-to-one>
        <property name="CategoryName" />
      </class>
    </hibernate-mapping>

Answer 1

我最近做了类似的事情,但EF作为数据.我不知道nhibernate知道相同的方法是否有效.

基本步骤是

• 确保从db加载目标集合并将其附加到对象图以进行更改跟踪
• .ForMember(dest => dest.Categories, opt => opt.UseDestinationValue())
• 然后创建一个自定义IObjectMapper,用于将IList <>映射到IList <T>,其中T:Entity

• 自定义IObject映射器使用了http://groups.google.com/group/automapper-users/browse_thread/thread/8c7896fbc3f72514中的一些代码.

  foreach (var child in source.ChildCollection)
  { 
      var targetChild = target.ChildCollection.SingleOrDefault(c => c.Equals(child)); // overwrite Equals or replace comparison with an Id comparison
      if (targetChild == null)
      { 
          target.ChildCollection.Add(Mapper.Map<SourceChildType, TargetChildType>(child));
      } 
      else
      { 
          Mapper.Map(child, targetChild);
      } 
  } 
  

• 最后,在sourceCollection中存在检查targetCollection中所有Id的最后一条逻辑,如果不存在则删除它们.

最终并不是那么多代码,并且可以在其他行动中重复使用.