QT QDebug with QIODevice not working

QT QDebug with QIODevice not working

I wanted my QT application to store certain logs in different files. I had
been using qDebug() << "LOG Messages" to output information. The problem
in this method is that all output will come on the same screen even if you
are threading. The QDebug class documents that I can make a
QDebug(QIODevice * dev) to give any QIODEvice as the device to store data.
So I wrote the following code but it doesnt work :
QString logfilePath = "/var/log/1.log";
QFile * logfile = new QFile(logfilePath);
if(!logfile->open(QIODevice::WriteOnly|QIODevice::Append)){
// There is an error
}else{
QDebug * logger = new QDebug(logfile);
*logger << "msg";
}
The file is created but no information is stored in the file. I even
checked the QDebug code and it looks like it creates a TEXT Stream on the
QIODevice. So why is no output being stored in the file ?
Also I know the qMessageInstaller function. But it wont work for me
because it is a universal handler and I would like different threads to
store log messages in different files.