C# delegate v.s. EventHandler

Question

I want to send an alert message to any subscribers when a trap occurred.

The code I created works fine using a delegate method myDelegate del.

My qu

Answer 1

It is much better to use an event for your example.

• An event is understood by the Visual Studio Form and WPF designers, so you can use the IDE to subscribe to events.

• When raising events, there is no need for you to write your own foreach handling to iterate through them.

• events are the way that most programmers will expect this functionality to be accessed.

• If you use a delegate, the consuming code can mess around with it in ways that you will want to prevent (such as resetting its invocation list). events do not allow that to happen.

As for your second question: Using an event you would create a class derived from EventArgs to hold the data, and pass that to the event when you raise it. The consumer will then have access to it.

See here for details: http://msdn.microsoft.com/en-us/library/system.eventargs.aspx