OperationContract 的集合返回类型以及如何添加到 DataContracts 列表中？

Question

我有一个业务领域对象 (BDO) 类：

public class BDO_LIST_DEPARTMENTS
{
    public int DEPARTMENT_ID { get; set; }
    public string DEPARTMENT_NAME { get; set; }
}

然后我有一个DataContract 类：

[DataContract]
public class DC_LIST_DEPARTMENTS
{
    [DataMember]
    public int DEPARTMENT_ID { get; set; }

    [DataMember]
    public string DEPARTMENT_NAME { get; set; }
}

在我的服务层中，我尝试将 BDO 转换为DataContract，然后返回此DataContract 的列表，作为OperationContract 的返回类型：

[OperationContract]
    IList<DC_LIST_DEPARTMENTS> GetAllDepartments();

这是我在服务层中最初的尝试：

public IList<DC_LIST_DEPARTMENTS> GetAllDepartments()
    {
        DC_LIST_DEPARTMENTS DCDepartment = new DC_LIST_DEPARTMENTS();
        IList<DC_LIST_DEPARTMENTS> DCListOfDepartments = new List<DC_LIST_DEPARTMENTS>();
        ICollection<BDO_LIST_DEPARTMENTS> BDOListOfDepartments = Bal.GetAllDepartments();

        foreach (BDO_LIST_DEPARTMENTS BDODepartment in BDOListOfDepartments)
        {
              DCDepartment.DEPARTMENT_ID = BDODepartment.DEPARTMENT_ID;
              DCDepartment.DEPARTMENT_NAME = BDODepartment.DEPARTMENT_NAME;
              DCListOfDepartments.Add(DCDepartment);
        }

        return DCListOfDepartments;
    }

如您所见，我尝试将单个DataContract 添加到IList<DataContract>，但是当我这样做时，它会将列表中的所有其他项目更改为具有相同细节的相同DataContract。

因此，我的问题是，OperationContract 的正确返回类型是什么，如何返回 DataContract 类的列表以及如何在不更改所有数据的情况下添加到该列表中列表中的其他项目？

Answer 1

定义收集数据合约

[CollectionDataContract]
public class DC_LIST_DEPARTMENTS_LIST : List<DC_LIST_DEPARTMENTS> {
  ...
}

并使用此集合数据合约作为操作方法的返回类型。

public DC_LIST_DEPARTMENTS_LIST  GetAllDepartments() {
   ...
}

这里是服务方法的修改实现：

public DC_LIST_DEPARTMENTS_LIST   GetAllDepartments() {

            IList<DC_LIST_DEPARTMENTS> DCListOfDepartments = new List<DC_LIST_DEPARTMENTS>();
            ICollection<BDO_LIST_DEPARTMENTS> BDOListOfDepartments = Bal.GetAllDepartments();

            foreach (BDO_LIST_DEPARTMENTS BDODepartment in BDOListOfDepartments) {
                DC_LIST_DEPARTMENTS DCDepartment = new DC_LIST_DEPARTMENTS() {
                    DEPARTMENT_ID = BDODepartment.DEPARTMENT_ID,
                    DEPARTMENT_NAME = BDODepartment.DEPARTMENT_NAME
                };
                DCListOfDepartments.Add(DCDepartment);
            }

            return DCListOfDepartments;
        }