QDataStream & operator<< ( QDataStream & s, const QFont & font )
 
(QDataStream & operator>> ( QDataStream & s+, QFont & font

QFont font1,font2;
 
QByteArray ba;
 
QDataStream ds(&ba,QIODevice::WriteOnly);
 
QDataStream ds2(&ba,QIODevice::ReadOnly);
 
ds<<font1;
 
 
ds2>>font2;

class A{
 
public:
 
A(){}
 
QString name;
 
qint32 age;
 
 
};

Q_DECLARE_METATYPE(A);

QDataStream &operator<<(QDataStream &out, const A &a){
 
out<<a.name<<(qint32)a.age;
 
return out;
 
}
 
QDataStream &operator>>(QDataStream &in, A &a){
 
in>>a.name>>a.age;
 
return in;
 
 
}

qRegisterMetaTypeStreamOperators<A>("A");

#include <QtCore>
 
class A{
 
public:
 
A(){}
 
QString name;
 
qint32 age;
 
};
 
Q_DECLARE_METATYPE(A);
 
QDataStream &operator<<(QDataStream &out, const A &a){
 
out<<a.name<<(qint32)a.age;
 
return out;
 
}
 
QDataStream &operator>>(QDataStream &in, A &a){
 
in>>a.name>>a.age;
 
return in;
 
}
 
int main(int argc, char *argv[])
 
{
 
QCoreApplication app(argc, argv);
 
qRegisterMetaTypeStreamOperators<A>("A");
 
A from,to;
 
from.name="mohammed alabdaly";
 
from.age=20;
 
QByteArray ba;
 
QDataStream ds(&ba,QIODevice::WriteOnly);
 
QDataStream ds2(&ba,QIODevice::ReadOnly);
 
QMetaType::save(ds,qMetaTypeId<A>(),&from);//كتابة بيانات المتغير
 
QMetaType::load(ds2,qMetaTypeId<A>(),&to);//قراءة بيانات المتغير
 
qDebug()<<QObject::tr("%1,%2").arg(to.name).arg(to.age);
 
 
return app.exec();