ok, it works fine for decompressing, but my scenario is a little bit different...
I have a directory (Master) containg other dirs (subs) with files in them, I need, if possible to report compression (zipping, not unzipping) of the Master directory, mantaining in the zip file the direcotry hierarchy?
Please excuse me for the misunderstanding. There is indeed a way to archive a hierarchy of folders with a progress bar with the same project. The easiest approach would be to utilize the ZipFile.CreateFromDirectory method that comes from "Telerik.Windows.Zip.Extensions".
I have modified the previous project by replacing the unarchiving functionality with the archiving one and adding the required references. I am attaching the project for your disposal so you can examine it and use it for your own purposes.