Wrapping a COM dll

If that is the case, is there anyway to write a Windows 32-bit DLL in vb?

For this task i code an interface Dll which can communicate with the COM dll through an self defined interface and then call this one.

Hope that helps
;) WoK

No way you must write you dll with C++
...

>>If that is the case, is there anyway to write a Windows 32-bit DLL in vb?

No.

You will have to write it in C++.

What does youre DLL do ?

Vin.

I may be able to help with the C++ code.

Vin.

Wolfgang or Vincent:

This DLL simply connects to a SQL server and executes a stored procedure that returns messages.  Fairly simple.

I would rather not rewrite the DLL in C++ (i don't know how) but is there a way to wrap it with ease?

I appreciate any input you can offer...

- Steve

>>I am working with an application that can
only "talk" with windows dll's.

What does the API for this DLL look like ?

You won't be able to do this without using C++.

Vin.  

Vincent, do you have any sample C++ code that i could look at?  Maybe something using ADO?  something that might help?

Or

Wolfgang, do you have any sample code of wrapping a COM dll?

I'll have a look and get back to you.

What do you want to do ?

Vin.

I would like either:
1.  to wrap my COM dll in C++
or
2.  to write a Windows dll that uses basic ADO functionality (recordset, command object, etc)

Anything you could provide would be helpful...

- STeve

Interesting...

Here's a thought: you say that your application (the one that needs to talk to the VB DLL) can oly "talk" to 32-bit DLLs. I don't know the language and the capabilities of that application, but it is possible to create objects and talk to them using sheer DLL calls. COM is written to be accessed by any language and - although it'll be a tough task to tackle - it can be done using functions already defined in system DLLs.

The function to look for is CoCreateInstance(Ex). Now I hope that you have an easy way of dealing with V-tables, otherwise you should create just a tiny wrapper in C++ only to call functions by name on a certain pointer (the fn should utilize AddRef, Release and QeryInterface calls at least, and possibly remove the burden of calling Invoke, GetIDsOfNames, GetTypeInfo and GetTypeInfoCount). That way you have a method of calling into any VB COM object, but you'll have to tackle quite a lot, I think.

Abel

Instead of creating a wrapper, I think it can also be done using only API calls. Think of utilizing DispGetIdsOfNames and DispInvoke, in adjunction with other helper function like SafeArrayAccessData, VariantInit, VariantClear, VariantCopy, SysAllocString, SysFreeString and the likes. Those are needed to deal with VARIANTs and BSTRs. You can look them all up in the MSDN documentation.

svfafel:

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thanks!
amp
community support moderator

2/6

Thank you all for the input....apologies for the delay...

We came up with an alternate solution at this time....