【转载】#370

You subscribe to a particular event in C# by defining an event handler-code that will be called whenever the event occurs (is raised). You then attach your event handler to an event on a specific object, using the += operator.

Below is an example where we define an event handler for the Dog.Barked event. Each time that kirby barks, we'll record the date and time of the bark in a list.

 1 private static List<DateTime> barkLog = new List<DateTime>();
 2 
 3 static void Main()
 4 {
 5     Dog kirby = new Dog("Kirby", 12);
 6     kirby.Barked += new EventHandler(kirby_Barked);
 7 
 8     kirby.Bark();
 9     Console.ReadLine();
10 
11     kirby.Bark();
12     Console.ReadLine();
13 }
14 
15 // Neither argument is used, for the moment
16 static void kirby_Barked(object sender, EventArgs e)
17 {
18     // Log kirby's barks
19     barkLog.Add(DateTime.Now);
20 }

Assuming that the Dog class fires its Barked event whenever we call the Bark method, our handler will get called whenever kirby barks.

原文地址：#370 - Subscribe to an Event by Adding an Event Handle