【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.

private static List<DateTime> barkLog = new List<DateTime>();

static void Main()
{
    Dog kirby = new Dog("Kirby", 12);
    kirby.Barked += new EventHandler(kirby_Barked);

    kirby.Bark();
    Console.ReadLine();

    kirby.Bark();
    Console.ReadLine();
}

// Neither argument is used, for the moment
static void kirby_Barked(object sender, EventArgs e)
{
    // Log kirby's barks
    barkLog.Add(DateTime.Now);
}

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