Call this member function to determine if the found file is compressed.
A compressed file is marked with FILE_ATTRIBUTE_COMPRESSED, a file attribute identified in the WIN32_FIND_DATA structure. For a file, this attribute indicates that all of the data in the file is compressed. For a directory, this attribute indicates that compression is the default for newly created files and subdirectories.
You must call FindNextFile at least once before calling IsCompressed.
See the member function MatchesMask for a complete list of file attributes.