Qt C++ QString to QByteArray Conversion

try using toUtf8() .. it works fine with me

I guess you should use:

QString::fromUtf8(const QByteArray &str)

Or:

QString::QString(const QByteArray &ba)

to convert QByteArray to QString, then write it into file by QTextStream.
After that, read file by QTextStream, use:

QString::toUtf8()

to convert QString to QByteArray.

QString::QString(const QByteArray &ba)

Constructs a string initialized with the byte array ba. The given byte array is converted to Unicode using fromUtf8().

P.S: Maybe use QFile::write and QFile::read is a better way.