Re: Passing parameters to a Com DLL
"WishfulDoctor" <WishfulDoctor@discussions.microsoft.com> wrote in
message news:B94CB0AA-D2A2-44C3-8CD4-42A4497F8891@microsoft.com
Actually, my first attempt had the variables as BSTR. I had the same
problem that my test program calling from a C++ returned correct
values, but the one in VB did not. So, I changed them all to Variant
You must have done something wrong. In my experience, it works.
Debug, check the .vt fields of VARIANT's you get in. My guess is, you
get variants of type VT_VARIANT | VT_BYREF, and the referred-to
variant in turn holds a string or an integer.
This is the crux of my limited knowledge - how do I debug the COM
routine being called by the VB program.
Project | Properties | Debugging. Set Command to the full path of VB
executable - or even VB IDE. Then set your breakpoints, and hit F5.
The call is correct - your expectations of possible parameter values
are not.
Since I am doing the calling - is there a way I can specify the
possible parameter values?
Well, in VB you can. For example, you define sName variable as "Dim
sName As Object": you could Dim it as String instead. You could also
change the call to
sSecret= it.GetSecret((sName), (sPwd), (iLevel))
Extra parentheses indicate pass by value, as opposed to by reference
(which is the default). But none of this works in VBScript, where all
variables are VARIANTs and all parameters are passed by reference.
--
With best wishes,
Igor Tandetnik
With sufficient thrust, pigs fly just fine. However, this is not
necessarily a good idea. It is hard to be sure where they are going to
land, and it could be dangerous sitting under them as they fly
overhead. -- RFC 1925