How to IgnoreDataMember attribute in WCF POCO Serialization

Introduction

POCO stands for PLAIN OLD CLR OBJECT.  If in WCF we are using

1.    Complex Data type  for example custom class
2.    And not attributing this custom class as DataContract  and properties of the class as DataMember
3.    If we want to expose the below custom class  to client  and not using DataContractSeraliazer  then all public properties will be automatically serialized

public class MyCustomData
    {public string Name { get; set; }public string RollNumber { get; set; }public string Subject { get; set; }
    }

 Automatically POCO (Plain old CLR Object) is serialized without using DataContract attribute.   
So to test this, let us create service contract

[ServiceContract]public interface IService1
    {
        [OperationContract]
        MyCustomData GetData();

    }

 And service implementation is as below

public class Service1 : IService1
    {public MyCustomData GetData()
        {
            MyCustomData data = new MyCustomData { Name = "John", RollNumber = "1", Subject = "WCF" };return data; 
        }

       
    }

 So when we consume this service at client side 

We can use that as above

Program.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using ConsoleApplication1.ServiceReference1;

namespace ConsoleApplication1
{class Program
    {static void Main(string[] args)
        {
            Service1Client proxy = new Service1Client();
            MyCustomData data = proxy.GetData();
            Console.WriteLine(data.Name + data.Subject + data.RollNumber);
            Console.ReadKey(true);
        }
    }
}

 Now we know how we could serialize custom data or class without using DataContractSerlializer.  But if we notice all the public property are serialized. If we want to hide some of public property from serialization then we will use IgnoreDataMember

public class MyCustomData
    {public string Name { get; set; }
        [IgnoreDataMember]public string RollNumber { get; set; }public string Subject { get; set; }
    }

Add the namespace System.RunTime.Serilization   to work with IgnoreDataMember attribute.
Now we are hiding public property RollNumber with IgnoreDataMember attribute , so at the client side when we try to access RollNumber property on custom class MyCustomData we will get the below compile time error. 

Error says there is no definition for RollNumber is present at the client side.that's all thank you for reading.