DotNetZip will give you what you want:
http://dotnetzip.codeplex.com/
It's both easy and simple to use. Listing a zipfile directory:
using (ZipFile zip = ZipFile.Read(ExistingZipFile))
{
foreach (ZipEntry e in zip)
{
if (header)
{
System.Console.WriteLine("Zipfile: {0}", zip.Name);
if ((zip.Comment != null) && (zip.Comment != ""))
System.Console.WriteLine("Comment: {0}", zip.Comment);
System.Console.WriteLine("\n{1,-22} {2,8} {3,5} {4,8} {5,3} {0}", "Filename", "Modified", "Size", "Ratio", "Packed", "pw?");
System.Console.WriteLine(new System.String('-', 72));
header = false;
}
System.Console.WriteLine("{1,-22} {2,8} {3,5:F0}% {4,8} {5,3} {0}", e.FileName, e.LastModified.ToString("yyyy-MM-dd HH:mm:ss"), e.UncompressedSize, e.CompressionRatio, e.CompressedSize, (e.UsesEncryption) ? "Y" : "N");
}
}
Nothing gets uncompressed. It just seeks to the end of the file, then seeks backwards to find the directory/manifest, then reads it.
If you discover that an entry is itself a zip file, and you want to explore that, it's easy to extract that as a temp file and recurse down to explore it, though if I remember right, you can
Edited To Note: DotNetZip used to live at Codeplex. Codeplex has been shut down. The old archive is still [available at Codeplex][1]. It looks like the code has migrated to Github:
- https://github.com/DinoChiesa/DotNetZip. Looks to be the original author's repo.
- https://github.com/haf/DotNetZip.Semverd. This looks to be the currently maintained version. It's also packaged up an available via Nuget at https://www.nuget.org/packages/DotNetZip/