You could write a function like this:
QString GetRandomString() const
{
const QString possibleCharacters("ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789");
const int randomStringLength = 12; // assuming you want random strings of 12 characters
QString randomString;
for(int i=0; i<randomStringLength; ++i)
{
int index = qrand() % possibleCharacters.length();
QChar nextChar = possibleCharacters.at(index);
randomString.append(nextChar);
}
return randomString;
}