Essential .NET, Volume 1: The Common Language Runtime

Contexts and Interception

The CLR gives context attributes the chance to put context properties in place as a context is being created. The CLR gives context properties the chance to inject message sinks between a proxy and a context-bound object when the object's proxy is created. One could argue that the primary motivation for context properties is to act as a factory for message sinks.

The message sinks injected by a context property are responsible for implementing the aspect that their property (and its attribute) represents. For example, our thread priority property would need to inject a message sink to adjust the thread priority prior to entering the context and then reset it upon leaving the context. Message sinks typically manipulate ...