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Events

Another new feature of COM+ is events. An event is a single call to a method on a COM interface, originated by the publisher and delivered by the COM+ Event service to the correct subscriber(s). A publisher is any program that makes the COM calls that initiate events. A subscriber is a COM+ component that receives calls (representing events) from a publisher. The subscriber implements an interface as a COM server; the publisher makes calls on that interface as a COM client (see Figure 13.4).

Figure 13.4. Publisher communicating to a subscriber using the COM+ Event subsystem.

Events represent a programming model that is able to support the ...