Delegates

[deanoA]

Can anybody show me the shortest example on using a delegate? Im just trying to gather ideas on how to program in "keep it short and simple way" :) "To teach is to learn twice"

[Blake Coverett]

The shortest example? Well I guess that would be...

class T{delegate void D();static void Main(){D d = new D(Main);d();}}

...but watch out for the stack overflow. -- -Blake (com/bcdev/blake)

[Blake Coverett]

The shortest example? Well I guess that would be...

class T{delegate void D();static void Main(){new D(Main)();}}

...but watch out for the stack overflow. I suppose you'd like a useful example?

class Example {
delegate void StatusOutput(string text);

static void Main() {
	DoSomeWork(new StatusOutput(System.Console.WriteLine));
	DoSomeWork(new StatusOutput(Alert));
}

static void Alert(string text) {
	System.Windows.Forms.MessageBox.Show(text, "Status Update");
}

static void DoSomeWork(StatusOutput output) {
	output("Working...");
	System.Threading.Thread.Sleep(2000);
	output("Done");
}

}

That was about the shortest meaningful use I could think of. A delegate is an object that wraps a method. You can then pass this object around and use it later to call the method. There are lots of other more advanced uses, like invoking them asynchronously, but that's a start. -- -Blake (com/bcdev/blake)