How to output the data from tablemodel?

[shalongbasi]

In the function sendSettingParameters(void) of class RemoteControl, I want to get all the data from QList<QList<QVariant> > stepTable in the class steptablemodel output to QDataStream "out" so that it can be send out through UDP socket. The way I tried with function stepTable2Stream() is not working. I tried to overload << for class steptablemode, but it cannot access stepTable from the overload function <<. How can I do it? Thanks. The data inside QList<QList<QVariant> > stepTable are int or float

@class RemoteContol : public QWidget
{
Q_OBJECT

public:
explicit RemoteContol(QWidget *parent = 0);
~RemoteContol();

private:
Ui::RemoteContol *ui;

QUdpSocket udpSocket;
quint8 baseTime;    // 0:GPS 1: UTC
quint8 opMode;      // 0:Manual 1:Auto
quint8 waveform;    // 0:FD 1:TD50 2:TD33 3:TD25
steptablemodel StepTableModel;

};
class steptablemodel : public QAbstractTableModel
{
Q_OBJECT
public:
explicit steptablemodel(QObject *parent = 0);
void setStepTable(QList<QList<QVariant> > &tablelist);
friend QDataStream& operator <<(QDataStream& out, const steptablemodel& steptable);
QDataStream stepTable2Stream();
signals:

public slots:
void insertAStep(QList<QVariant> step, const QModelIndex &index);
private:
QList<QList<QVariant> > stepTable;
};

void RemoteContol::sendSettingParameters(void)
{
float a=2.3;
QByteArray datagram;
QDataStream out(&datagram,QIODevice::WriteOnly);
out.setVersion(QDataStream::Qt_4_6);
out.setByteOrder(QDataStream::LittleEndian);
out.setFloatingPointPrecision(QDataStream::SinglePrecision);
out << baseTime;
if (opMode==0) { //manual mode
out << opMode;
if (ui->FreqSetcomboBox->currentIndex()==0)
out << (float)ui->FREQSetBox->value();
else
out << 1/(float)ui->FREQSetBox->value();
out << (float) ui->CurrentSetBox->value()
<< (quint8) 0 << waveform
<< (quint16) ui->VoltageSetBox->value()
<< (quint8) ui->PowerspinBox->value();
} else { // auto stepping table mode
out = StepTableModel.stepTable2Stream(); <---- here causes the problem
}
udpSocket.writeDatagram(datagram,QHostAddress("10.10.10.255"),49166);
}

QDataStream steptablemodel::stepTable2Stream()
{
QDataStream stream;
stream << stepTable.size();
for (int i=0; i<stepTable.size(); i++) {
stream <<stepTable[i][0].toFloat()<<stepTable[i][1].toFloat()
<<stepTable[i][2].toInt();
if (stepTable[i][3].toString().compare("FD")==0)
stream << (quint8) 0;
else if (stepTable[i][3].toString().compare("TD50")==0)
stream << (quint8) 1;
else if (stepTable[i][3].toString().compare("TD33")==0)
stream << (quint8) 2;
else if (stepTable[i][3].toString().compare("TD25")==0)
stream << (quint8) 3;
stream <<stepTable[i][4].toInt()<<stepTable[i][5].toInt();
}
return stream;
}
@

[Mario84]

I guess your problem is that the QDataStream (as the name already says) is a stream, which means it does not store the data itself, it is just a class used for serialization into a QIODevice.
So you should either use the stream to write to such a device inside stepTable2Stream() or return your data as something like a QByteArray and put that into a stream outside...