Question

I have a service contract as follow

[ServiceContract]
public interface IService
{
     [MyCustomBehavior]
     [OperationContract]
     void MyOperation();
}

The question is whether a call to

 new ChannelFactory<IService>(myBinding, myUri)

Will implicitly add MyCustomBehavior before the call, just by virtue of me passing the IService to the ChannelFactory or will I need to dig deeper and explicitly set MyCustomBehavior to the MyOperation operation?

Answer 1

Operation Behaviors

Operation behaviors, which implement the IOperationBehavior interface,
are used to extend both the client and service runtime for each
operation.

There are two mechanisms for adding operation behaviors to an
operation. The first mechanism is to create a custom attribute to be
used on the method that models the operation. When an operation is
added to either a ServiceHost or a ChannelFactory, WCF adds any
IOperationBehavior attributes to the behaviors collection on the
OperationDescription created for that operation.

The second mechanism is by directly adding the behavior to the
behaviors collection on a constructed OperationDescription.

I will suggest you to read this first.

Configuring and Extending the Runtime with Behaviors