The best VB6 solution for ZIP / UNZIP

[dima69]

I'm looking for the solution to Zip / Unzip files in VB6 / VBA.
I've searched the web and found several solutions (zlib.dll, Info-Zip, DynaZip, PKZip, ...). The question is which one is the best ?
My considerations are:
1. The solution must be simple, general and robust (be able to unzip all standard zip files, run on all Win platforms).
2. The solution must be based on standard DLL (not OCX, not command-prompt EXE)
3. No extra features required (password protection, multiple volumes, SFX)

[SanjuMtr]

I'm looking for the solution to Zip / Unzip files in VB6 / VBA.
I've searched the web and found several solutions (zlib.dll, Info-Zip, DynaZip, PKZip, ...). The question is which one is the best ?
My considerations are:
1. The solution must be simple, general and robust (be able to unzip all standard zip files, run on all Win platforms).
2. The solution must be based on standard DLL (not OCX, not command-prompt EXE)
3. No extra features required (password protection, multiple volumes, SFX)

you can use Pkzip/Pkunzip ...I have use it & its works fine.I gave the sample code for this earlier.for further information plz check my threads.

[dima69]

you can use Pkzip/Pkunzip ...I have use it & its works fine.I gave the sample code for this earlier.for further information plz check my threads.

Thanks, I've seen this thread, but I'me looking for another solution (see post #1 para. 2)

[Killer42]

Thanks, I've seen this thread, but I'me looking for another solution (see post #1 para. 2)

the answer might depend a bit on what you mean by "all Windows platforms". Since WinXP has built-in zip file handling (never mind how good or bad the interface), it should be possible to find a a way to tap into that. But I imagine a Windows 3.0 PC might have a problem with that.

[dima69]

the answer might depend a bit on what you mean by "all Windows platforms". Since WinXP has built-in zip file handling (never mind how good or bad the interface), it should be possible to find a a way to tap into that. But I imagine a Windows 3.0 PC might have a problem with that.

Well, I think that the reasonable assumption would be to require Windows 98 and above.

[Killer42]

Well, I think that the reasonable assumption would be to require Windows 98 and above.

Fair enough. I can't remember - does Win98 handle zip files ("compressed folders") itself? Or was that introduced later? If later, then that's obviously not an option.

[Killer42]

By the way, I did a little hunting on the web. Here are some links that may be of interest, with the original descriptions (I didn't write them)...

• Info-ZIP's ZIP libraries
  Info-ZIP's purpose is to "provide free, portable, high-quality versions of the Zip and UnZip compressor-archiver utilities that are compatible with the DOS-based PKZIP by PKWARE, Inc." - and they do an excellent job at it. Download their free Zip and Unzip DLLs here.
• Zlib
  zLib is a "A Massively Spiffy Yet Delicately Unobtrusive Compression Library (Also Free, Not to Mention Unencumbered by Patents)" [ahem - that really is how the authors introduce it!] The compression algorithm used is essentially the same as used in PKZip and gzip. This is the home page for the algorithm with C code and specifications; however if you want to use it in VB, then go to:
• Mark Nelson's OCX for ZLib
  A nice, free, fully working OCX providing access to Zlib compression and decompression. MFC source code is included. Recommended!
• www.info-zip.org
  This last one definitely seems worth a look (Killer42)

[dima69]

Thanks a lot to Killer for the detailed reply.
For now, I am implementing the ZLib.dll, based on the example given on Paradoxes.info
From my point of view, the advantages of zlib are:
1. Single and relatively small dll, for both compression and extraction.
2. Very liberal license, sutable for commercial use.
The disadvantages: VB implementation is not straight-forward, file handling is not included in dll, only the base data compression and decompression.

I'd be glad to see any additional comments on this.