QtableWidget does not show data - c++

Question

I have a class that creates random data which I would like to show in a tableview on the main window.
I added via Designer a table view to the main window and called it tblData.
I suspect the problem is related to this because when I call the constructor the ui file with some implementation is already there.
I have taken the "Detailed Description" section from http://qt-project.org/doc/qt-5/qtablewidget.html as guidance....
However, the table remains empty. I do not see why... Thank you very much.
include "mainwindow.h"
#include "ui_mainwindow.h"
#include <QDebug>
MainWindow::MainWindow(QWidget *parent) :
QMainWindow(parent),
ui(new Ui::MainWindow)
{
ui->setupUi(this);
QStringList headers;
headers << "Datapoints";
Dataset *myData;
myData = new Dataset();
myData->createRandomData(10); // create a ten element vector
QVector<int> data;
data = myData->getDataVector(); // data vector created in class Dataset
qDebug() << data;
int i;
for (i = 0 ; i < data.size() ; i++){
QString datapoint;
datapoint = QString::number(data[i]);
QTableWidgetItem * newItem = new QTableWidgetItem(datapoint);
ui->tblData->setItem(i, 0, newItem); // works not
qDebug() << datapoint; // works
}
}
MainWindow::~MainWindow()
{
delete ui;
}

Answer 1

I think you have to define your table's dimensions before starting to populate it with the data, i.e.
ui->tblData->setRowCount(data.size());
ui->tblData->setColumnCount(1);
The reason is that by default the initial row and column count of the table is 0, so the newly added items are not visible.