Paste code

#ifndef ASK_H
#define ASK_H
#include "QDialog"
#include "QStandardItemModel"
using namespace std;
#include <QtGui/QMainWindow>
#include "ui_untitled.h"

class DialogI : public QWidget
{
    Q_OBJECT
 Ui::Form u;
 int n;
public:
    DialogI(QWidget * parent = 0, Qt::WindowFlags f = 0);
 signals: 
     void Next(int n, double*f); 

 private slots: 
     void okClicked(); 
     void setn(); 

};
#endif


#include <qlineedit.h>
#include <qpushbutton.h>
#include <qvalidator.h>
#include "Ask.h"

DialogI::DialogI (QWidget * parent, Qt::WindowFlags f): QWidget (parent, f)
{
 u.setupUi(this);
 n = 0;
 connect(u.btnOk, SIGNAL(clicked()), this, SLOT(okClicked()));
 connect(u.spinBox, SIGNAL(valueChanged(int)), this, SLOT(setn()));
}


void DialogI::okClicked()
{
 int i, j;
 bool p = true;
 QVector <double> m (n*n);
 for (i = 0; i < n; i++)
  for (j = 0; j < n; j++)
   m[i + n*j] = u.tableWidget->item(i, j)->text().toDouble(&p);;
}

void DialogI::setn()
{
 int k = u.spinBox->value(); 
 if (n != k) 
  {
   u.tableWidget->setRowCount(n);
            u.tableWidget->setColumnCount(n);
 }
}