I have previously used MiniZip (zlib wrapper) to unzip archives. MiniZip cannot be used for Metro applications as it uses deprecated APIs in "iowin32.c" -- CreateFile() and SetFilePointer().
I thought that would be an easy fix and created "iowinrt.c" with CreateFile() and SetFilePointer() replaced with CreateFile2() and SetFilePointerEx(). While this way I obtained a version of MiniZip that uses only approved Win8 APIs, it still turned out to be useless -- I forgot about sandboxing. If I pick a file using FileOpenPicker() and pass its path to my modified MiniZip I still cannot open it -- CreateFile2() will fail with "Access is denied." message.
So it appears that old C API for file access if now mostly useless; it is my understanding that in order to fix this I would need to reimplement my "iowinrt" in C++/CX using the new async file access. Are there any other options? I think I saw somewhere that WinRT does have compress/uncompress functionality but that it only works on individual files, not archives.
Additional requirements it that I need this to work in memory.
For a moment I thought I had a solution via .NET Framework 4.5:
I found this piece of info about how to create .NET classes that can be used from C++/CX: http://social.msdn.microsoft.com/Forums/en-US/winappswithnativecode/thread/3ff383d0-0c9f-4a30-8987-ff2b23957f01
.NET Framework 4.5 contains ZipArchive and ZipArchiveEntry classes in System.IO.Compression: http://msdn.microsoft.com/en-us/library/system.io.compression.ziparchive%28v=vs.110%29.aspx#Y0 http://msdn.microsoft.com/en-us/library/system.io.compression.ziparchiveentry%28v=vs.110%29.aspx#Y0
I thought I could create C# Metro