7Zip files aren't supported as a non-seekable stream (ReaderFactory) because the format requires seeking in order to read the contents. This is documented here: http://sharpcompress.codeplex.com/wikipage?title=Supported%20formats&referringTitle=Home
Using ArchiveFactory to read 7Zip files doesn't load everything into memory but it does require a seekable stream or a local file.
Using ArchiveFactory to read 7Zip files doesn't load everything into memory but it does require a seekable stream or a local file.