C# 0 The Complete Reference

X

 and 

Y

, which also define event 

handlers compatible with 

MyEventHandler

. Thus, these handlers can also become part 

of the event chain. Notice that the handlers in 

X

 and 

Y

 are not 

static

. This means that objects 

of each must be created, and the handler linked to each instance must be added to the event 

chain. The differences between instance and 

static

 handlers is examined in the next section.

Instance Methods vs. Static Methods as Event Handlers

Although both instance methods and 

static

 methods can be used as event handlers, they do 

differ in one important way. When a 

static

 method is used as a handler, an event notification 

applies to the class. When an instance method is used as an event handler, events are sent to 

specific object instances. Thus, each object of a class that wants to receive an event notification 

must register individually. In practice, most event handlers are instance methods, but, of 

course, this is subject to the specific application. Let’s look at an example of each.

The following program creates a class called 

X

 that defines an instance method as an 

event handler. This means that each 

X

 object must register individually to receive events. 

To demonstrate this fact, the program multicasts an event to three objects of type 

X

.

/* Individual objects receive notifications when instance

   event handlers are used. */

using System;

// Declare a delegate type for an event.

delegate void MyEventHandler();

// Declare a class that contains an event.

class MyEvent {

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