压缩和解压文件，不使用MFC，无Lib和DLL封装的原始cpp文件-XZip and XUnzip provide non-MFC functions to create a zip, add files to it, and extract files from it- all in two .cpp files

zlib xzip封装，压缩解压接口调用简单，适用于学习及zip库使用。-zlib xzip package, compression decompression interface calls simply for learning and zip libraries.