How to get Date & Time from NTP server and update my system clock.... using QT Widget application

[Sekhar]

Can any one tell me how to get Date and Time from NTP server and synchronize with system clock? using QT widget application?
i got a code from internet but it does not working.....

mainWindow.cpp

#include "mainwindow.h"
#include "ui_mainwindow.h"

unsigned char buf[10];

MainWindow::MainWindow(QWidget *parent) :
    QMainWindow(parent),
    ui(new Ui::MainWindow)
{
    ui->setupUi(this);
}

MainWindow::~MainWindow()
{
    delete ui;
    udpSocket->close();
}

void MainWindow::changeEvent(QEvent *e)
{
    QMainWindow::changeEvent(e);
    switch (e->type()) {
    case QEvent::LanguageChange:
        ui->retranslateUi(this);
        break;
    default:
        break;
    }
}

void MainWindow::on_Update_clicked()
{
    QHostInfo info = QHostInfo::fromName("time.nist.gov");//("0.pool.ntp.org");
    QString ipAddress = info.addresses().first().toString();
    ui->ipAddress->setText(ipAddress);
    udpSocket = new QUdpSocket(this);

    connect(udpSocket, SIGNAL(readyRead()), this, SLOT(readPendingDatagrams()));
    connect(udpSocket, SIGNAL(connected()), this, SLOT(connectSuccsess()));
    udpSocket->abort();
//    udpSocket->connectToHost("time.nist.gov",123);//("0.pool.ntp.org", 123);

}
void MainWindow::readPendingDatagrams()
{
   // ui->statusLabel->setText("Reading...");
    QByteArray newTime;
    QDateTime Epoch(QDate(1900, 1, 1));
    QDateTime unixStart(QDate(1970, 1, 1));
    do {
        newTime.resize(udpSocket->pendingDatagramSize());
        udpSocket->read(newTime.data(), newTime.size());
    } while(udpSocket->hasPendingDatagrams());

    QByteArray TransmitTimeStamp ;
    TransmitTimeStamp = newTime.right(8);

    quint64 seconds = 0;
    for (int i=0; i<= 3; ++i)
    {
         seconds = (seconds << 8) | TransmitTimeStamp[i];
    }
    ui->plainTextEdit->appendPlainText(QString::number(seconds, 10));
    QDateTime newestTime;
    newestTime.setTime_t(seconds - Epoch.secsTo(unixStart));
     ui->plainTextEdit->appendPlainText(newestTime.toString());
}
void MainWindow::connectSuccsess()
{
   // ui->time->setText("Connected");
    ui->time->setText("Connected-jkjlk");
    QByteArray timeRequest(48, 0);
    timeRequest[0] = '\x23';
    udpSocket->flush();
    udpSocket->write(timeRequest);
}

//////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////

MainWindow.h 

#ifndef MAINWINDOW_H
#define MAINWINDOW_H

#include <QMainWindow>
#include <QAbstractSocket>
#include <QUdpSocket>
#include <QHostInfo>
#include <QHostAddress>
#include <QDateTime>

namespace Ui {
class MainWindow;
}

class MainWindow : public QMainWindow
{
    Q_OBJECT

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

protected:
    void changeEvent(QEvent *e);

private slots:
    void on_Update_clicked();
    void readPendingDatagrams();
    void connectSuccsess();
private:
    Ui::MainWindow *ui;
    QUdpSocket *udpSocket;
};

#endif // MAINWINDOW_H

[jsulm]

@Sekhar said in How to get Date & Time from NTP server and update my system clock.... using QT Widget application:

i got a code from internet but it does not working

Please tell us what exactly does not work, or do you expect us to guess?

[SGaist]

Hi,

And to add to @jsulm, this is usually a task managed by a system service. You will also have to request higher privilege to modify your system's clock.

[Sekhar]

@jsulm
thanks for your response. i would like to get the date and time from NTP server not form System(Date & Time) this is my primary task. I don't know how to get the data from NTP server.
and in the above code i was tried but got the wrong timestamp(date and time) like 16th jan 2036.