The DataContract of WCF

The custom data type passed between the client and the server, in the following format:

[DataContract] Public classUser:iextensibledataobject {[DataMember] Public intID {Get;Set; } [DataMember] Public stringName {Get;Set; }
There is no [DataMember], it means that it is not passed Public stringSex {Get;Set; }
And there's no [DataMember], it's going to be passed Publicextensiondataobject ExtensionData {Get;Set; } }

For implementing interface IExtensibleDataObject, the purpose is to ensure that data is not lost. However, if a DTO is passed between the client and the server to ensure that the version is consistent, the interface may not be implemented.

The benefits of implementing IExtensibleDataObject are as follows:

The server returns the latest version of User:

                 Public User GetName ()                {                      returnnew  User {                                                     ID=1,                              Name=" Apple " ,                              Sex="M"                      };                }

The client version is not up-to-date and has no ID:

When the client requests:

Private Static void Main (string[] args)            {                  new  userinfoclient ();                   var user = client. GetName (); At this point the user is no ID, because there is no update service, resulting in version inconsistency                  Console.readkey ();            }

At this point the extensiondata of the interface is working, it contains the ID, so that the data is not lost:

The DataContract of WCF