hey that is really helpful but
i want to ask can some one guide me building Quazip and Zlib by Qt creator in build Cmake
i don't want to download separate Cmake and perform all these commands in it
i tried to do this and i guess i was partially succesfull

i got this Msg in my application output while running Zlib
zlib version 1.3.1 = 0x1310, compile flags = 0x65
uncompress(): hello, hello!
gzread(): hello, hello!
gzgets() after gzseek: hello!
inflate(): hello, hello!
large_inflate(): OK
after inflateSync(): hello, hello!
inflate with dictionary: hello, hello!

and i found these files in my build folder = libzlib.dll
libzlib.dll.a
and other files
but when i tried to build Quazip it did not gone as planed i got so many errors
so can someone pls give its answer too i really appreciate that.

You mean how to replace QTextCodec with QStringConverter? (QTextStream remains the same in Qt6 as in Qt5)
I've only used QStringConverter for the case shown above but there are more info for example here

it worked. thanks @VRonin

Yes I use the builtin Qt zlib

Thank you @ambershark I have added the following line in the quazip project .pro :

Now I can compile it.

@mrjj

Solve the problem loading the data is this way.
QDataStream out(&dstFile);
out.writeRawData(ba.data(), ba.size());

And works like a charm!
Thank you!