DLL's Compatibility

[Krishnaa]

ConvertStringToBSTR is declared in comutils.h.

You can use ConvertBSTRToString to get your char* back from BSTR if needed in C++ application.

[cheery_poori]

Hello..,

I have tried using BSTR but i want my DLL to be compatible in C, Borland C++, VB, VC++, Java and .Net..so if i use BSTR then i wont be able to use it in basic 'C'., is there any other way to do so...

[Siddhartha]

I have developed a DLL in VC++, i want to use it in VB and VB.net.. When i try to use the DLL in vb it is giving...

Perhaps the standard way of exposing functionality developed in C++ to an automation client like VB is by using COM. i.e. Making your class Automation-COM compliant will allow you to use functionality using standard VB syntax, like this -

Set objectName = CreateObject ("YourDllName.ClassName")

objectName.DoSomething ()

Further read:

• Post + Sample: Invoking functionality in a C++ COM DLL from VB Script Client
• Post + Sample: Invoking functionality in a C++ COM DLL from VB.NET Client

The approach you have chosen so far is to use the export functionality of a "C" style DLL - a relatively outdated mechnism when compared to DLLs programmed in C++ that are COM compliant.

COM compliance brings with it the advantage of adhering to standards designed for cross-language programming capabilities.

[Igor Vartanov]

I have tried using BSTR but i want my DLL to be compatible in C, Borland C++, VB, VC++, Java and .Net..so if i use BSTR then i wont be able to use it in basic 'C'., is there any other way to do so...

What a mistake! BSTR type is a generic type for COM. Since COM is applicable for basic 'C' (is it a surprise for you?), so the BSTR type does.

And what about Borland C++? Do you think it's kinda extraterrestrial in Windows world? Or C++ world?