C# 如何在c wcf上正确使用重载构造函数

我正在学习一个教程，并试图以json格式传递一些数据。 我试图使构造函数过载，认为它将显示不同的数据，但事实并非如此

在这两种情况下，我得到相同的输出

这是我的界面：

namespace JsonWcfService
{
    [ServiceContract]
    public interface IGetJson
    {

        // display user`s department
        [OperationContract]
        [WebInvoke(Method = "GET",
            ResponseFormat = WebMessageFormat.Json,
            BodyStyle = WebMessageBodyStyle.Wrapped,
            UriTemplate = "json/userDepartment/{name}")]
        List<Departments> userDepartments(string name);


        // display user`s app
        [OperationContract]
        [WebInvoke(Method = "GET",
            ResponseFormat = WebMessageFormat.Json,
            BodyStyle = WebMessageBodyStyle.Wrapped,
            UriTemplate = "json/userApp/{name}")]
        List<Departments> userApp(string name);       

    }
}

这是我的班级：

namespace JsonWcfService
{
    public class GetJson : IGetJson
    {

        //display user`s departments
        public List<Departments> userDepartments(string name)
        {
            List<Departments> listUserDepartments = new List<Departments>();
            using (SqlConnection conn = new SqlConnection(ConfigurationManager.ConnectionStrings["tabletConnection"].ToString()))
            {
                conn.Open();

                string cmdStr = String.Format("SELECT users.userName, users.departmentID, department.departmentName, users.isActive FROM users,department "
                    + "WHERE users.departmentID = department.departmentID "
                    + "AND userName = '" + name +"'");
                SqlCommand cmd = new SqlCommand(cmdStr, conn);
                SqlDataReader rd = cmd.ExecuteReader();

                if (rd.HasRows)
                {
                    while (rd.Read())
                        listUserDepartments.Add(new Departments(rd.GetString(0), rd.GetInt32(1), rd.GetString(2), rd.GetString(3)));
                }
                conn.Close();
            }
            return listUserDepartments;
        }


        //display user`s app
        public List<Departments> userApp(string name)
        {
            List<Departments> listUserApp = new List<Departments>();
            using (SqlConnection conn = new SqlConnection(ConfigurationManager.ConnectionStrings["tabletConnection"].ToString()))
            {
                conn.Open();

                string cmdStr = String.Format("SELECT * FROM application");
                SqlCommand cmd = new SqlCommand(cmdStr, conn);
                SqlDataReader rd = cmd.ExecuteReader();

                if (rd.HasRows)
                {
                    while (rd.Read())
                        listUserApp.Add(new Departments(rd.GetInt32(0), rd.GetString(1)));
                }
                conn.Close();
            }

            return listUserApp;
        }

    }


    [DataContract]
    public class Departments
    {
        [DataMember]
        public int departmentId { get; set; }
        [DataMember]
        public string departmentName { get; set; }
        [DataMember]
        public string userName { get; set; }
        [DataMember]
        public string isActive { get; set; }

        public Departments(int temp_departmentId, string temp_departmentName)
        {
            departmentId = temp_departmentId;
            departmentName = temp_departmentName;
        }

        public Departments(string temp_userName, int temp_departmentId, string temp_departmentName, string temp_isActive)
        {
            userName = temp_userName;
            departmentId = temp_departmentId;
            departmentName = temp_departmentName;
            isActive = temp_isActive;
        }
    }
}

构造函数1的输出：

{userAppResult:[{departmentId:1，departmentName:A，isActive:null，userName:null}，{departmentId:2，departmentName:A，isActive:null，userName:null}，{departmentId:3，departmentName:A，isActive:null，userName:null}，{departmentId:4，departmentName:A，isActive:null，userName:null}，{departmentId:5，departmentName:A，isActive:null}]

构造函数2的输出：

---

{userDepartmentsResult:[{departmentId:1，departmentName:A，isActive:Y，userName:b}，{departmentId:2，departmentName:A，isActive:Y，userName:b}，{departmentId:3，departmentName:A，isActive:Y，userName:b}

这与重载无关。您试图让WCF不序列化没有值集的属性。序列化程序不知道您调用了哪个构造函数，因此它只会序列化整个对象，包括标记为DataMember的所有属性

有几种方法可以做到这一点。可以将DataMember属性的EmitDefaultValue设置为false以忽略具有默认值的属性，如和中所述

您也可以使用

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还要注意的是，如果这是为了学习，我建议研究ASP.NETWebAPI而不是WCFREST。您还应该使用，而不是使用用户提供的变量通过字符串连接手工制作SQL

您希望获得什么样的输出？放弃本教程。如果要构建REST服务，请使用ASP.NET WebAPI。您对内联SQL的使用也使您的服务容易受到SQL注入攻击。我已经更新了问题，添加了输出I getWell，当您执行选择时，选择返回什么？构造函数1 userAppResult不应该只返回departmentId和departmentName吗？这就是我正在努力实现的目标。