Mega Code Archive

Delphicallingvbdll

> Can someone point me to an explanation and examples on how > Delphi 4/5 can > call a VB6 DLL? > I'm going on the assumption you mean "a VB6 ActiveX dll". If you mean otherwise, feel free to ignore this message and I apologize for misunderstanding. Anyway, the first thing you need to do is to register the target dll. (Regsvr32.exe <dll name> will do the trick) Once you've done that, open up Delphi and start your project you want to use it from. Then, go Project|Import Type Library and scroll until you find the dll you want to use. (It may not have the same name as the dll, so you'll probably need to know the classname or the company that made it, etc.) Highlight it, then go down to the lower left corner and uncheck the "Generate Component Wrapper" option. I have found that trying to use these "wrappers" is an exercise in futility. It does a great job on simple modules, but more complex ones (especially if they have more than one class) are next to useless through the wrapper. Anyway, then click the "Create Unit" button. This will create a file called <dllname>_TLB.pas for use in your program. This will contain all of the information that could be extracted from the interface and is what you need to start programming with. All of the classes in the file should be of the format _<classname>. VB prefixes all classes with an underscore...I could bore you with the details of why, but that's not for here. *8) Anyway, to use a class, say _MyClass, it's pretty straightforward. PROCEDURE TMyForm.CreateVBDLLObject; VAR objMyClass : _MyClass; BEGIN objMyClass := coMyClass.Create; objMyClass.MyRoutine; objMyClass := NIL; END; There will always be an associated co-class, so in this instance, it's coMyClass. Use that to create the object, and use the _MyClass object type reference to hold what it returns. Anyway, I hope this is what you were asking...if not ... well, maybe someone else lurking on the list could use the information. Todd Lang