I have a Unix timestamp and I need to convert it to human readable date + time. How can it be done in Qt?
int unixTime = 1234567890;
QDateTime timestamp;
timestamp.setTime_t(unixTime);
qDebug() << timestamp.toString(Qt::SystemLocaleShortDate);
That should get you going. Like Matthew said, see QDateTime.setTime_t, as well as QDateTime.toString. The toString has an enumeration with several different options, as well as an overload where you can pass a string allowing however much customization you like.
QDateTime.setTime_t
You can use the static function: "fromTime_t", like:
qDebug() << QDateTime::fromTime_t(your_time_stamp).toString("dd/MM/yyyy hh:mm:ss");
One good example
qint64 qiTimestamp=QDateTime::currentMSecsSinceEpoch();
QDateTime dt;
dt.setTime_t(qiTimestamp/1000);
ui->lineEdit_DateTime->setText(dt.toString("yyyy-MM-dd hh:mm:ss"));
Note that QDateTime::setTime_t() has been deprecated, use QDateTime::setSecsSinceEpoch(). Same for fromTime_t(): use QDateTime::fromSecsSinceEpoch().
As mentioned, instead of using the obsolete _t members here is a working example (Qt 5).
qint64 llTS=1591132400;
QString szFull=QDateTime::fromSecsSinceEpoch(llTS).toString("dddd d MMMM yyyy hh:mm:ss");
szFull: Tuesday 2 June 2020 23:13:20
Source: QDateTime (Qt 5)
Date formatting: QDate
Time formatting: QTime
Related
I have 2 QDateEdit which are Date_dob and Date_doj.
I am storing the value using a Qstring shown below.
QString str_dob(ui->DATE_dob->text());
QString str_doj(ui->DATE_doj->text());
Now i want to populate the same into ui->Date_dob and ui->Date_doj (after some editing event takes place). I have used ,
ui->DATE_dob->setText(s.at(2));
ui->DATE_doj->setText(s.at(5)); //where s is a string having data
but the data doesn't populate.
Any kind of suggestion will be extremely appreciated.
Thanks in advance
For convert QString to QDate you can use QDate::fromString(). Then you can set date in QDateEdit with QDate::setDate(const QDate &date).
Hope it help.
You use wrong way the conversion.
QDate to QString
QString str_dob = ui->DATE_dob->toString("dd MM yyyy");
in the date format you should specify it else your conversation is default format. Known Format you can use
QString to QDate
if( ui->DATE_dob->setDate(QDate::fromString(str_dob,"dd MM yyyy").year()\
,QDate::fromString(str_dob,"dd MM yyyy").month()\
,QDate::fromString(str_dob,"dd MM yyyy").day()){
// Your Conversation Succes
}
when QString to QDate you have to know date format in string else your conversation fail or wrong value you get.
Example: if Qstring is : 19/12/2017 than your format is "dd/MM/yyyy"
I have a QJsonObject data and want to convert to QString. How can I do this? Searched for help in Qt, it only can convert QJsonObject to QVariantMap...
Thanks in advance.
Remembering when I first needed to do this, the documentation can be a bit lacking and assumes you have knowledge of other QJson classes.
To obtain a QString of a QJsonObject, you need to use the QJsonDocument class, like this: -
QJsonObject jsonObj; // assume this has been populated with Json data
QJsonDocument doc(jsonObj);
QString strJson(doc.toJson(QJsonDocument::Compact));
we can do this in one line
QString strFromObj = QJsonDocument(jsonObject).toJson(QJsonDocument::Compact).toStdString().c_str();
When the macro QT_NO_CAST_FROM_ASCII is enabled, you can do something like:
QJsonDocument doc(jsonObject);
QByteArray docByteArray = doc.toJson(QJsonDocument::Compact);
QTextCodec *codec = QTextCodec::codecForName("UTF-8");
Qstring strJson = codec->toUnicode(docByteArray);
Or better, just use QLatin1String(QByteArray&), based on the example of TheDarkKnight:
QJsonDocument doc(jsonObj);
QByteArray docByteArray = doc.toJson(QJsonDocument::Compact);
Qstring strJson = QLatin1String(docByteArray);
Is there a way in Qt3 to convert QDateTime into a QString and back to QDateTime, so that eventually QDateTime will contain information about milliseconds?
Thanks.
Use the toString function. The format parameter determines the format of the result string.
For example the following code will return only the seconds and the miliseconds.
QDateTime t = QDateTime::currentDateTime ();
QString s = t.toString("ss:zzz");
PS. You should consider porting your code to Qt4
QString DataList[100][100] ;
QDateTime AwbDateTime ;
AwbDateTime = QDateTime::fromString(DataList[i][9].left(19),Qt::ISODate) ;
This will work fine in Qt3
I'm having trouble with a seemingly very simple problem: I want to get a QDateTime from a QString containing a timestamp. I got the timestamp from PostgreSQL, but it doesn't matter. Here is the code that does not work:
QString timestamp = "2010-10-09 19:21:46+02:00";
QString format = "YYYY-MM-DD HH:MM:SSTZD";
QDateTime dt = QDateTime::fromString(timestamp, format);
qDebug() << dt.toString(); // outputs empty string
There must be something very obvious I'm missing. Thanks!
There were two mistakes I was making. There is no TZD in the format specifications, so I removed the time zone information since I do not need it in my app by doing:
timeStamp.chop(6);
And then used the following format to get a QDateTime. Note the lowercase format characters:
QDateTime createdAt = QDateTime::fromString(timeStamp, "yyyy-MM-dd HH:mm:ss");
Thanks to everyone above for helping out.
I wish QDateTime overrode the - operator and returned a QTimeSpan representing the difference between two QDateTimes (just like .NET's TimeSpan). Since this doesn't exist in Qt, I decided to implement it.
Unfortunately, QDateTime has no msecsTo-like function. What is the cleanest way to get the difference between two QDateTimes accurate to the millisecond?
I realize that this question is from 2010, and that Qt 4.7 didn't exist back then (it actually came out about a week after this question was originally asked--September 21 2010), but for people who are looking for how to do this now:
As of Qt 4.7, QDateTime has a "msecsTo" method. See Qt 4.8 documentation at http://doc.qt.io/qt-4.8/qdatetime.html#msecsTo.
QDateTime dateTime1 = QDateTime::currentDateTime();
// let's say exactly 5 seconds pass here...
QDateTime dateTime2 = QDateTime::currentDateTime();
qint64 millisecondsDiff = dateTime1.msecsTo(dateTime2);
// millisecondsDiff is equal to 5000
I would probably use a.daysTo(b)*1000*60*60*24 + a.time().msecsTo(b.time()). Note that you need to watch how close you can be, since you're going to overflow your data type rather quickly.
how about this:
QDateTime a = QDateTime::currentDateTime();
QDateTime b = a.addMSecs( 1000 );
qDebug( "%d", a.time().msecsTo( b.time() ) );
Source
All the solutions are good, but if your timestamp is in a particular format then you can find the difference by below, and also you can assign that to QString.
let start is time on some moment in some format
QString start = QDateTime().currentDateTime().toString("hh:mm:ss AP dd/MM/yyyy");
let end is time on some moment after start in some format
QString end = QDateTime().currentDateTime().toString("hh:mm:ss AP dd/MM/yyyy");
So, you can find the difference by providing the format and using msecsto and assign them to QString(if required).
QString timeDiff= QString("%1").arg(QDateTime().fromString(start ,"hh:mm:ss AP dd/MM/yyyy").msecsTo(QDateTime().fromString(end ,"hh:mm:ss AP dd/MM/yyyy")));