Hossein
10th October 2015, 20:28
I tried to use a simple `QTimer` object on my window widget so that I can calculate the elapsed time a method takes to complete.
But to my astonishment! the timer was blocked until the method completes execution! i.e when the method in question ends, the timer starts ticking!!
Here is a sample code to demonstrate what I wrote:
#ifndef MAINWINDOW_H
#define MAINWINDOW_H
#include <QMainWindow>
namespace Ui {
class MainWindow;
}
class MainWindow : public QMainWindow
{
Q_OBJECT
public:
explicit MainWindow(QWidget *parent = 0);
~MainWindow();
private slots:
void on_btnTest_clicked();
void OnTimerTick();
private:
Ui::MainWindow *ui;
ulong seconds;
};
#endif // MAINWINDOW_H
#include "mainwindow.h"
#include "ui_mainwindow.h"
#include "opencv2/core/core.hpp"
#include "opencv2/highgui/highgui.hpp"
#include "opencv/cv.h"
#include <QTimer>
#include <QtCore>
MainWindow::MainWindow(QWidget *parent) :
QMainWindow(parent),
ui(new Ui::MainWindow)
{
ui->setupUi(this);
}
MainWindow::~MainWindow()
{
delete ui;
}
void MainWindow::on_btnTest_clicked()
{
QTimer * timer = new QTimer(0);
seconds =0;
connect(timer,SIGNAL(timeout()),this,SLOT(OnTimerT ick()));
timer->setInterval(100);
timer->start();
QThread::sleep(5);//simulating a method which takes 5 seconds to complete
//timer->stop();
}
void MainWindow::OnTimerTick()
{
ui->lblElapsedTime->setText(QString::number(++seconds));
}
How can I get the asynchronous behavior, something like what we have in C#? where the Timer runs its own thread of execution?
But to my astonishment! the timer was blocked until the method completes execution! i.e when the method in question ends, the timer starts ticking!!
Here is a sample code to demonstrate what I wrote:
#ifndef MAINWINDOW_H
#define MAINWINDOW_H
#include <QMainWindow>
namespace Ui {
class MainWindow;
}
class MainWindow : public QMainWindow
{
Q_OBJECT
public:
explicit MainWindow(QWidget *parent = 0);
~MainWindow();
private slots:
void on_btnTest_clicked();
void OnTimerTick();
private:
Ui::MainWindow *ui;
ulong seconds;
};
#endif // MAINWINDOW_H
#include "mainwindow.h"
#include "ui_mainwindow.h"
#include "opencv2/core/core.hpp"
#include "opencv2/highgui/highgui.hpp"
#include "opencv/cv.h"
#include <QTimer>
#include <QtCore>
MainWindow::MainWindow(QWidget *parent) :
QMainWindow(parent),
ui(new Ui::MainWindow)
{
ui->setupUi(this);
}
MainWindow::~MainWindow()
{
delete ui;
}
void MainWindow::on_btnTest_clicked()
{
QTimer * timer = new QTimer(0);
seconds =0;
connect(timer,SIGNAL(timeout()),this,SLOT(OnTimerT ick()));
timer->setInterval(100);
timer->start();
QThread::sleep(5);//simulating a method which takes 5 seconds to complete
//timer->stop();
}
void MainWindow::OnTimerTick()
{
ui->lblElapsedTime->setText(QString::number(++seconds));
}
How can I get the asynchronous behavior, something like what we have in C#? where the Timer runs its own thread of execution?