Convert System::Datetime to QDateTime

Question

How can I convert System::Datetime to QDateTime?

You may want to take a look at [this question](http://stackoverflow.com/questions/4030511/convert-a-qdatetime-in-utc-to-local-system-time) and [this answer](http://stackoverflow.com/a/30930959/5653461) from another question. — IAmInPLS, Apr 01 '16 at 09:32
Possible duplicate of [QDateTime Conversion](http://stackoverflow.com/questions/30930085/qdatetime-conversion) — kawashita86, Apr 01 '16 at 09:47

score 0 · Answer 1 · edited May 23 '17 at 11:52

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Perhaps this is straightforward method, but it can be easy for understating:

a) convert System::Datetime to string with DateTime.ToString()

b) convert string to QDateTime with QDateTime::fromString()

Or consider usage of QDateTime::fromTime_t() (see example of Datetime to time_t conversion)

edited May 23 '17 at 11:52

Community

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answered Apr 01 '16 at 09:34

VolAnd

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score 0 · Answer 2 · answered Apr 01 '16 at 10:28

using Win32 API

#define WINDOWS_TICKS_PER_SEC 10000000
#define EPOCH_DIFFERENCE 11644473600LL

QDatetime getQDatetime(){
    FILETIME ft = {0}; 
    ::GetSystemTimeAsFileTime(&ft);  //Retrieves the current system date and time.
    LARGE_INTEGER li = {0};
    li.LowPart = ft.dwLowDateTime;
    li.HighPart = ft.dwHighDateTime;
    long long int hns = li.QuadPart;
    wprintf(L"Windows API time: %lli\n", hns);
    long long int utm ;
    utm=(hns / WINDOWS_TICKS_PER_SEC - EPOCH_DIFFERENCE);
    wprintf(L"Unix time: %lli\n", utm);
    return QDateTime::fromTime_t(utm);
}

See this for more help

Convert Windows Filetime to second in Unix/Linux : http://stackoverflow.com/a/6161842/2731967 — Ankur, Apr 01 '16 at 10:42

score 0 · Answer 3 · answered Apr 01 '16 at 11:20

You can use the ISO 8601 norm as intermediate format :

/* not tested */
System::DateTime date;
QString str(date.ToString("O")); // "O" for ISO format
QDateTime qdt = QDateTime::fromString(str, Qt::ISODate);

See QDateTime::fromString and DateTime::ToString docs

score 0 · Accepted Answer · answered Apr 05 '16 at 06:53

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QDateTime::fromString(QString::fromStdWString(msclr::interop::marshal_as<std::wstring>(systemDateTime.ToString("ddMMyyyy HH:mm:ss"))), "ddMMyyyy HH:mm:ss"))

answered Apr 05 '16 at 06:53

Ayoub

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Convert System::Datetime to QDateTime

4 Answers4