Item 25: Implement the Event Pattern for Notifications(Effective C#)

Events provide a standard syntax for notifying listeners. The .NET Event Pattern follows the event syntax to implement the Observer Pattern. Any number of clients can attach handlers to the events and process them. Those clients need not be known at compile time. Events don’t need subscribers for the system to function properly. Using events in C# decouples the sender and the possible receivers of notifications. The sender can be developed completely independently of any receivers. Events are the standard way to broadcast information about actions that your type has taken.