Component-based Programming with .NET Final Exam

• everything that must be exposed by a WCF service 
• explains how the service may be accessed by the client

• address
• binding
• contract

a full network address where the service is being hosted

a description of the communication protocol the client is expected to use to communicate with the service

• a description of the semantics required to exchange messages with the service
• and interface with method prototypes

• implementing a service contract is hosted by the service and never by the client.
• defining data contracts are serialized by the service and deserialized by the client so the client has a local copy of the object.

An interface can be decorated with the [ServiceContract] attribute and its methods decorated with the [OperationContract] attribute.

a data class can be decorated with the [DataContract] attribute and its member variables decorated with the [DataMember] attribute.

• suitable for cross-platform communication 
• .NET client consumes a Web Service
• uses XML-based messaging (not efficient)

• only suitable for communication between .NET clients and services.
• binary format (efficient)

built-in binding only works for pure .NET solutions running on a single computer

• Single
• PerCall
• PerSession

new object is activated to service each method call

new object is activated to service each client session

• decorating a class with with variations of the [ServiceBehaviour] attribute.
• e.g. [ServiceBehaviour(InstanceContextMode = InstanceContextMode.PerCall)]

• 1. adding a reference to a custom library containing the required service and data contracts.
• 2. adding a service reference to the specific service as long as the service is running at the time and the service supports MEX

metadata exchange

a proxy class will be generated in the client project which hides any WCF-specific code.

a service contract that is implemented by a client of a WCF service and used by the service to update the client whenever a significant event has occurred in the service object.