Convert a QByteArray to a QVariantList

[franco.amato]

Hi to all,
reading the documentation seems easy but I can not convert a QByteArray to a QVariantList.
I know that first I have to convert it to a QVariant and then I append to a QVariantList.

I wrote this code:
in my class declaration I have

class UserData
{
        public:
QByteArray m_fpData;//352bytes
QByteArray& fingerData(){ return m_fpData; }
 
    ..more code..
}

class UserData
{
        public:
QByteArray m_fpData;//352bytes
QByteArray& fingerData(){ return m_fpData; }

    ..more code..
}

To copy to clipboard, switch view to plain text mode 

and in a method of another class I have

bool Device::registerNewUser(UserData* user)
{
	QList<QVariant> paramList;
 
	//cardId
	QString cardId = QString::number( user->cardId(), 10 );
 
	//fp data
	QByteArray& b = user->fingerData(); //I get the reference to the bytearray
	QVariant v;
	v.setValue(b); //I add it to a QVariant
	QVariantList fingerData;
	fingerData.append(v); //and finally to a QVarianList
      ...more code...
 
}

bool Device::registerNewUser(UserData* user)
{
	QList<QVariant> paramList;

	//cardId
	QString cardId = QString::number( user->cardId(), 10 );

	//fp data
	QByteArray& b = user->fingerData(); //I get the reference to the bytearray
	QVariant v;
	v.setValue(b); //I add it to a QVariant
	QVariantList fingerData;
	fingerData.append(v); //and finally to a QVarianList
      ...more code...

}

To copy to clipboard, switch view to plain text mode 

Unfortunately I get invalid pointer of the QVariant. This is strange to me as from documentation of QVariant a QVariant accept a reference to a QByteArray as constructor:

QVariant::QVariant ( const QByteArray & val )
Constructs a new variant with a bytearray value, val.

QVariant::QVariant ( const QByteArray & val )
Constructs a new variant with a bytearray value, val.

To copy to clipboard, switch view to plain text mode 

So I don't know how to solve my problem