Implement the IInstanceContextProvider interface to provide the appropriate System.ServiceModel..::.InstanceContext object to the system. Typically, this interface is implemented to support shared sessions, enable service instance pooling, control lifetimes of service instances, or to group contexts among clients.

For example, to implement sharing, insert a custom IInstanceContextProvider to decide which session or call from a client is associated with which InstanceContext object. For an example that demonstrates the sharing of instance contexts, see InstanceContextSharing.

Note:
When an IInstanceContextProvider is inserted into Windows Communication Foundation (WCF), the normal property that controls the creation of InstanceContext objects (the ServiceBehaviorAttribute..::.InstanceContextMode property) is no longer checked and has no effect.

A more generic mechanism by which you can initialize InstanceContext objects when created (for example, to attach custom extensions to each InstanceContext) is the System.ServiceModel.Dispatcher..::.IInstanceContextInitializer.

Windows 7, Windows Vista, Windows XP SP2, Windows Server 2008 R2, Windows Server 2008, Windows Server 2003

.NET Framework

Reference