Datacontract and servicecontract difference

Question

As far as I knw -

ServiceContract can be used for interface/class whereas DataContract can b used only for Class, Struct and Enums

Apart from this - what are other differences b/w these 2 ? When DataContract and ServiceContract should be used in an application ?

Any sample or link would also do. Thanks in advance.

Answer 1

The ServiceContract defines the service's contract - its shape and form. It defines the name of the service, its XML namespace etc., and it's typically an interface (but could also be applied to a class) that contains methods decorated with the [OperationContract] attribute - the service methods.

[ServiceContract] public interface IMyService {     [OperationContract]     Response GetData(int someKey); } 

The DataContract is a totally different beast - it decorates a class to define it as a class that's being used as a parameter or return value from one of the service methods. It's labeling that class as a "thing" to serialize onto the wire to transmit it. It's an instruction for the WCF runtime (the data contract serializer) that this class is intended to be used in a WCF service.

[DataContract] public class Response {      [DataMember]      int Key { get; set; }      [DataMember]      string ProductName { get; set; }      [DataMember]      DateTime DateOfPurchase { get; set; } } 

So the service contract and the data contract are two totally separate parts that play together to make a WCF service work - it's not like one could replace the other or something.