From: Graham Ford <graham@...>
Date: 2006-06-09T01:35:42+09:00
Subject: Win32OLE, COM, pointer arguments

I am trying to call a COM DLL with Win32OLE, but I am running into an 
issue with passing an argument to the method call.  The following works 
in Perl:

-- begin Perl

use Win32::OLE;
use Win32::OLE::Variant;

my $engine = Win32::OLE->new('X.X') or die 'Cannot load engine DLL: 
'.$!;
my $system = 'C:\path\to\dir';
my $mode = 0;
my $retVal = Variant(VT_I4|VT_BYREF, 0);
my $rc;

$rc = $engine->Execute($system,$mode,$retVal);
print "Return Code: ".Win32::OLE->LastError."\n";
print "Return Val: ".$retVal;

-- end Perl

In ruby I think it should look like this:

-- begin Ruby

require 'win32ole'
engine = WIN32OLE.new('X.X')

retVal = 1
rc = 1

rc = engine.Execute('C:\path\to\dir',0,retVal)

print "Return Code: ",retVal

-- end Ruby

When I run the ruby code, the DLL executes and processes the directory, 
but I need to be able to get back the return value.  Unlike in Perl, 
ruby doesn't seem to be able to generate a variant object to be passed 
to the method call.  The DLL expects an integer pointer for the third 
argument, COM signature VT_I4|VT_BYREF, but I'm at a loss as to how to 
properly pass this so I can retrieve the value after execution.

I've also tried olegen.rb to generate a ruby class for the DLL, but this 
seems to have the same exact problem.

Thanks,
Graham

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