简单的zip文件可以考虑 qUncompress，不行的话用第三方库就好了
QByteArray qUncompress ( const QByteArray & data )
Uncompresses the data byte array and returns a new byte array with the uncompressed data.
Returns an empty QByteArray if the input data was corrupt.
This function will uncompress data compressed with qCompress() from this and any earlier Qt version, back to Qt 3.1 when this feature was added.
Note: If you want to use this function to uncompress external data compressed using zlib, you first need to prepend four bytes to the byte array that contain the expected length (as an unsigned integer) of the uncompressed data encoded in big-endian order (most significant byte first).
See also qCompress().
QByteArray qUncompress ( const uchar * data, int nbytes )
This is an overloaded function.
Uncompresses the first nbytes of data and returns a new byte array with the uncompressed data.
