Qtime

satyanarayana143

how to display time with nanoseconds

SGaist

Hi,

You can mix qDebug and std::chrono duration.

You should give more information about want you want to do.

satyanarayana143

i tried but not coming exactly give some code

satyanarayana143

#include "mainwindow.h"
#include "ui_mainwindow.h"
#include <chrono>
#include <iomanip>
#include <iostream>

std::chrono::time_point<std::chrono::system_clock> now = std::chrono::system_clock::now();
auto duration = now.time_since_epoch();
typedef std::chrono::duration<int, std::ratio_multiply<std::chrono::hours::period, std::ratio<1>
        >::type> Days; /* UTC: +8:00 */

Days days = std::chrono::duration_cast<Days>(duration);
duration -= days;
auto hours = std::chrono::duration_cast<std::chrono::hours>(duration);
duration -= hours;
auto minutes = std::chrono::duration_cast<std::chrono::minutes>(duration);
duration -= minutes;
auto seconds = std::chrono::duration_cast<std::chrono::seconds>(duration);
duration -= seconds;
auto milliseconds = std::chrono::duration_cast<std::chrono::milliseconds>(duration);
duration -= milliseconds;
auto microseconds = std::chrono::duration_cast<std::chrono::microseconds>(duration);
duration -= microseconds;
auto nanoseconds = std::chrono::duration_cast<std::chrono::nanoseconds>(duration);
std::cout << hours.count() << ":"<< minutes.count() << ":"<< seconds.count() << ":"
      << milliseconds.count() << ":" << microseconds.count() << ":" << nanoseconds.count() << std::endl;


auto now1 = std::chrono::high_resolution_clock::now();
auto time = std::chrono::system_clock::to_time_t(now1);
auto tm = *std::gmtime(&time);
auto epoch = now1.time_since_epoch();
auto us = std::chrono::duration_cast<std::chrono::microseconds>(epoch).count() % 1000000;
std::cout << std::put_time(&tm, "%F %T.") << us; //<< std::put_time(&tm, " %Z\n");

this is my code where i am doing wrong

//     QDateTime myDateTime = QDateTime::fromMSecsSinceEpoch(ns / 1000000);

// const qlonglong nanosecs = 5555555;

// QDateTime myDateTime = QDateTime::fromMSecsSinceEpoch(nanosecs / 1000000);

Christian Ehrlicher

Still no idea what you want to achieve and what you think what is not working.
QDateTime can not handle nanoseconds.

satyanarayana143

@satyanarayana143 said in Qtime:

how to display time with nanoseconds

i want to display time with nanoseconds

Christian Ehrlicher

@satyanarayana143 said in Qtime:

i want to display time with nanoseconds

Then don't use QDateTime or handle the nanoseconds separately from QDateTime

satyanarayana143

i am not using qdatetime chrono librariy iam using

Christian Ehrlicher

@satyanarayana143 So why do you ask in a Qt forum then?

satyanarayana143

i want to display in qt

JonB

@satyanarayana143
Then make a string of it and display it in a QLabel.

satyanarayana143

time not coming properly what is the mistake in code

Christian Ehrlicher

@satyanarayana143 said in Qtime:

time not coming properly

This is no error description and has nothing to do with Qt at all...