QDateTime時區的擷取方法

#include <QCoreApplication>
#include <QDateTime>
#include <stdlib.h>
#include <iostream>

// helper functions
QString getTimezoneDiff( QDateTime dt );

int main(int argc, char *argv[])
{
 QCoreApplication app(argc, argv);

 QDateTime localDate = QDateTime::fromString("2009-07-11 16:53:00","yyyy-MM-dd hh:mm:ss");

 QString diffStr;
 diffStr = getTimezoneDiff( localDate );

 

 printf ("Local Date: %s/r/n", localDate.toString().toLatin1().data() );
 //printf ("UTC   Date: %s/r/n", utcTime.toLatin1().data() );
 printf ("Offset    : %s/r/n", diffStr.toLatin1().data()  );

 

      return 0;
}

/**
 * QString getTimezoneDiff( QDateTime dt )
 * @param dt well formated date time (YYYY-MM-DD hh:mm:ss)
 * @return tzDiff (<+->hhmm)
 *
 * Purpose: return a timezone offset string to feed to PostgreSQL
 */
QString getTimezoneDiff( QDateTime dt ) {

 QString   localdt = dt.toString ( "hhmm" );  // get the local time part from the @param
 QString   utcDT = dt.toUTC().toString ( "hhmm" ); // get the UTC time part from the @param
 QString   tzDiff;     // this will hold the returned timezone diff.
 qint8     hhmmdt = localdt.toInt();
 qint8     hhmmUTC= utcDT.toInt();
 qint8   offset = hhmmdt - hhmmUTC;

 // is it a positive offset?
 if (offset>=0) {
  tzDiff = "+" + tzDiff.setNum(offset);;
 }
 else
  tzDiff.setNum(offset);
 return tzDiff;
}