Back to Questions
3.2k
views3
comments
unit type
f#


I have a windows forms button and I attach a function to its Click event, how can I make the function evaluate to the unit type?

let button = new Button()

button.Click.Add(buttonClicked)



let buttonClicked (e:System.EventArgs) =

let d = MessageBox.Show(e.ToString())

printf "" // stupid way of forcing the expression to evaluate to the unit type .. (?)



Any suggestions?
.
Hi,

"()" is used to represent unit. It's very general and can be used in a number of situations, for example;

> let x = fun () -> ();;
val x : unit -> unit

> x;;
val it : (unit -> unit) = <fun:clo@0>

> x();;
val it : unit = ()

Cheers,

Andy

By on 5/23/2007 2:32 PM ()
thank you for the quick (and correct!) reply :)
By on 5/23/2007 2:39 PM ()
You probably want to use the ignore function to make something evealuate to the unit type.

let buttonClicked (e:System.EventArgs) =
MessageBox.Show(e.ToString()) |> ignore

I'm probably going to start sounding like a broken record, but this is covered at the beginning of chapter 4 in my book:
[link:www.amazon.com]
By on 5/23/2007 9:06 PM ()

    Topic tags

    IntelliFactory Offices Copyright (c) 2011-2012 IntelliFactory. All rights reserved.
    Home | Products | Consulting | Trainings | Blogs | Jobs | Contact Us     		Built with WebSharper