Versioning round trip in WCF

Question

Hi,

As far as my knowledge is concerned about Versioning round trip in WCF, its about preserving unknown/additional data members. This can be achieved on implementing IExtensibleDataObject<m:smallfrac m:val="off"><m:dispdef><m:lmargin m:val="0"><m:rmargin m:val="0"><m:defjc m:val="centerGroup"></m:defjc></m:rmargin></m:lmargin></m:dispdef></m:smallfrac> interface in Data Contracts. I have defined a Data Contract as following:

 [DataContract]
 public class EmpInfo:IExtensibleDataObject
    {
        [DataMember]
        public int EmpID;
        [DataMember]
        public string EmpName;
        #region IExtensibleDataObject Members
        private ExtensionDataObject extensionData;
        public ExtensionDataObject ExtensionData
        {
            get { return extensionData; }
            set { extensionData = value; }
        }
        #endregion

    }

My service implementation is as following:

 public EmpInfo GetEmployeeData(EmpInfo info)
 {
            return new EmpInfo { EmpID = info.EmpID, EmpName = info.EmpName};
  }

I am consuming the service fro client using the following code: I am sending one additional Data Member "EmpAddress" in the EmpInfo  class and receiving the response from the service.

  static void Main(string[] args)
        {
            using (MyServiceClient proxy = new MyServiceClient())  
            {
                var sc = proxy.GetEmployeeData(new EmpInfo { EmpID = 1, EmpName = "AA", EmpAddress="MM"});
                Console.WriteLine("Employee ID: " + sc.EmpID);
                Console.WriteLine("Employee Name: " + sc.EmpName);
                Console.WriteLine("Employee Address: " + sc.EmpAddress);
              }
            Console.ReadLine();  

        }

As I have implemented my Data Contract from IExtensibleDataObject interface, I am expecting that the additional/unknown value sent by client(i.e EmpAddress) would not be lost and returned in round trip. But while, I am printing the value of "EmpAddress" in console, it is displayed as blank. What could be reason of this behaviour? Where I am doing the mistake?

Thanks in advance.

Regards

ronit_rc

Answer 1

Hi,

I think your problem is here:

 public EmpInfo GetEmployeeData(EmpInfo info)
 {
            return new EmpInfo { EmpID = info.EmpID, EmpName = info.EmpName};
  }

You are returning a New EmpInfo object and not the object that was sent in the first place.

Try this:

 public EmpInfo GetEmployeeData(EmpInfo info)
 {
            return new EmpInfo { EmpID = info.EmpID, EmpName = info.EmpName, ExtensionData = info.ExtensionData};
  }

Answer 2

Hi,

Thanks a lot for your answer. It worked.

Regards

ronit_rc