Finishing The DLL

The final step is to build the DLL.  On the "Build" menu, select "Build".   Make sure you have "Win32 Release" selected as the build type.  There isn't any reason to use a Debug version of the DLL in VB.

If you have any errors, then download the source code that I provided.  You can compare your version to mine, or simply use my wrapper code as a starting point.

Summary

This tutorial should have demonstrated how to create a DLL and export VB compatible functions. The first step is to actually create a skeleton DLL project, then to populate it with functions defined with __declspec(dllexport) WINAPI, then to finally to create a .def file to export non-mangled function names.

Improvement And Extension

With the zlib library you can compress and decompress binary streams of data.  To gain this functionality, you can export the compress (or compress2) and uncompress functions.  Such functions could be used to create your own file format or to compress and decompress data sent over a TCP/IP connection.   If you're creating an online game, you may want to consider compressing data before sending it.

You can also use the techniques shown in this tutorial to create your own functions in a C/C++ DLL to create accelerated functions to use within VB.  Instead of creating seperate DLLs, you can easily add your functions to the  zip DLL to make it easier to update.

References

zlib Home Site (http://www.gzip.org/zlib/)