Chapter 15. Delegates, Events, and Lambda Expressions

This chapter examines three innovative C# features: delegates, events, and lambda expressions. A delegate provides a way to encapsulate a method. An event is a notification that some action has occurred. Delegates and events are related because an event is built upon a delegate. Both expand the set of programming tasks to which C# can be applied. The lambda expression is a relatively new syntactic feature that offers a streamlined, yet powerful way to define what is, essentially, a unit of executable code. Lambda expressions are often used when working with delegates and events because a delegate can refer to a lambda expression. (Lambda expressions are also very important to LINQ, which is described in Chapter 19.) Also examined are anonymous methods, covariance, contravariance, and method group conversions.