Calling COM method

StephenLL has asked for the wisdom of the Perl Monks concerning the following question:

Hello all, I would like to translate the following vb(a) code over to Perl but I have not had any success. I have read the doc on win32 and ole but I can not get this to work.

I have a COM DLL which has a method called RLVersion. The way I call it in VBA is the following:

Set MyObject = CreateObject("RL.RLClass")
call MyObject.RLVersion(1,y)
msgbox(y)
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The 1 tells it the number of output arguements and y is obviously the output arguement. It passed back a 6 character string.

and this works fine.

Here is one of my many attempts at converting it to Perl. The WIn32::OLE works, but calling the RLVersion (method) does not.

use Win32::OLE qw(in with);
my $RL = Win32::OLE->new('RL.RLlass') or die "oops\n";
my $myoutput = $RiskLib->RiskLibVersion->Call(1);
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I would appreciate any help. I need to prove that this can work before I can start to learn perl and move completely away from vb/vbscript.

Thanks for any help you can provide.

Stephen

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Re: Calling COM method
by Mr. Muskrat (Canon) on Feb 05, 2005 at 21:55 UTC

You created the Win32::OLE object as $RL but you're trying to use $RiskLib in the next line.
my $myoutput = $RiskLib->RiskLibVersion->Call(1); does not appear to be a direct translation of call MyObject.RLVersion(1,y) so how did you arrive at this Perl statement?

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Re^2: Calling COM method

by StephenLL (Initiate) on Feb 05, 2005 at 23:04 UTC

My problem is that I don't know how to translate the CALL to perl. I have tried and searched through the perldocs, win32::api, this site and googled. When I try the following I get the error "Can not call method "RiskLibVersion" on an undefined value at myprog.pl line 3

use Win32::OLE qw(in with);
my $RL = Win32::OLE->new('RiskLib.RiskLibclass') or die "oops\n";
call $RL->RiskLibVersion(1,$y);
print $y;
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Thanks

Stephen

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Re: Calling COM method
by Jenda (Abbot) on Feb 05, 2005 at 23:30 UTC

In the VB code you pass two parameters to the RLVersion(), you should do the same in Perl. You just need to tell Win32::OLE that you want that parameter passed by reference. Something like this might help:

use Win32::OLE::Variant;
my $y = Variant(VT_BSTR || VT_BYREF, "");
$RL->RLVersion(1, $y);
print $y;
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Jenda
We'd like to help you learn to help yourself
Look around you, all you see are sympathetic eyes
Stroll around the grounds until you feel at home
-- P. Simon in Mrs. Robinson

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