Why doesn the zlib OCX work with VB5?
The zlib OCX that I published in the January 1997 Dr. Dobb’s Journal created a simple control that could be used to perform raw compression on a single file at a time. (Unfortunately, some users are getting the OCX sans documentation, and have the mistaken notion that it will work with ZIP format archives.) The control was written using Visual C++ 4.2, with MFC handling all of the ActiveX work. Unfortunately, the older versions of MFC seem to have some problems with VB5 and recent versions of other languages. For reasons that don’t seem to have anything to do with zlib, users of this OCX are finding that it GPFs or otherwise behaves poorly in their environments. Rather than spending a lot of time trying to debug MFC, I instead built a new version of the OCX using Visual C++ 5.0 and the Active Template Library (ATL). The ATL is Microsoft’s framework of the month, so presumably it should work properly with all of their products. So far it seems as though the new version of the control is
