From: Ralph Mason <ralph.mason@...>
Date: 2002-01-31T14:34:56+09:00
Subject: Re: Win32API and dll programming in windows

WARNING: I haven't used Win32api.

But the function you are calling returns a float, and I assume that 'n' or
number is a fixnum.  So there is a datatype problem in the return. You want
to give a return type of float

Ralph

----- Original Message -----
From: "Raphael Clancy" <rafemonkey@yahoo.com>
Newsgroups: comp.lang.ruby
To: "ruby-talk ML" <ruby-talk@ruby-lang.org>; <undisclosed-recipients:>
Sent: Thursday, January 31, 2002 6:13 PM
Subject: Win32API and dll programming in windows


> Can anyone recomend a good reference on Win32API and dll programming in
> general? I'm trying to get my head aroud it, but can't seem to make
> things work. I decided to start out with a very simple function, which
> had the signature:
>
> float GetDllVersion ();
>
> Looking at tha I can see that it doesn't want any arguments, and should
> return a float. Knowing that I try to call it like so:
>
> dllVer = Win32API.new("NameOfDll", "GetDllVersion", [], 'n')
>
> I use [] for the import array 'cause I'm not passing anything to the
> dll, and 'n'for the export because the function should return a number.
> Then I call the function like so:
>
> vers = dllver.call()
> puts "version: #{vers}"
>
> I run it, and get "version: 0", and I know from the documentation that
> it should be version 1.03. the 0 makes me think that 'vers' never gets
> anything put in it at all. Perhaps I'm missing the point of the import
> array? should I be passing a 4 byte array to the dll, and letting it put
> it's answer in that? did I forget to wave the dead chicken?
>
> I'm going to go beat on this some more, but any help would be
> apreciated!
>
> Thanks, R.
>