qdatetime.3qt

Qt/Embedded是一个多平台的C++图形用户界面应用程序框架

.TH QDateTime 3qt "10 November 2000" "Trolltech AS" \" -*- nroff -*-
.\" Copyright 1992-2000 Trolltech AS.  All rights reserved.  See the
.\" license file included in the distribution for a complete license
.\" statement.
.\"
.ad l
.nh
.SH NAME
QDateTime \- Date and time functions
.SH SYNOPSIS
.br
.PP
\fC#include <qdatetime.h>\fR
.PP
.SS "Public Members"
.in +1c
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.BI "\fBQDateTime\fR () "
.br
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.BI "\fBQDateTime\fR ( const QDate & ) "
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.BI "\fBQDateTime\fR ( const QDate &, const QTime & ) "
.br
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.BI "bool \fBisNull\fR () const"
.br
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.BI "bool \fBisValid\fR () const"
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.BI "QDate \fBdate\fR () const"
.br
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.BI "QTime \fBtime\fR () const"
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.BI "void \fBsetDate\fR ( const QDate & date ) "
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.BI "void \fBsetTime\fR ( const QTime & time ) "
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.BI "void \fBsetTime_t\fR ( uint secsSince1Jan1970UTC ) "
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.BI "QString \fBtoString\fR () const"
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.BI "QDateTime \fBaddDays\fR ( int days ) const"
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.BI "QDateTime \fBaddSecs\fR ( int secs ) const"
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.BI "int \fBdaysTo\fR ( const QDateTime & ) const"
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.BI "int \fBsecsTo\fR ( const QDateTime & ) const"
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.BI "bool \fBoperator==\fR ( const QDateTime & dt ) const"
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.BI "bool \fBoperator!=\fR ( const QDateTime & dt ) const"
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.BI "bool \fBoperator<\fR ( const QDateTime & dt ) const"
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.BI "bool \fBoperator<=\fR ( const QDateTime & dt ) const"
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.BI "bool \fBoperator>\fR ( const QDateTime & dt ) const"
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.BI "bool \fBoperator>=\fR ( const QDateTime & dt ) const"
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.SS "Static Public Members"
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.BI "QDateTime \fBcurrentDateTime\fR () "
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.SH RELATED FUNCTION DOCUMENTATION
(Note that these are not member functions.)
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.BI "QDataStream & \fBoperator<<\fR (QDataStream & " "s" ", const QDateTime & " "dt" ")"
.br
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.BI "QDataStream & \fBoperator>>\fR (QDataStream & " "s" ", QDateTime & " "dt" ")"
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.SH DESCRIPTION
The QDateTime class provides date and time functions.
.PP
A QDateTime object contains a calendar date and a clock time (a "datetime"). It is a combination of the QDate and QTime classes. It can read the current datetime from the system clock. It provides functions for comparing datetimes and for manipulating a datetime by adding a number of seconds or days.
.PP
A QDateTime object is typically created either by giving a date and time explicitly, or by using the static function currentTime(), which makes a QDateTime object which contains the system's clock time.
.PP
The date() and time() functions provide access to the date and time parts of the datetime. The same information is provided in textual format by the toString() function.
.PP
QDateTime provides a full set of operators to compare two QDateTime objects. A datetime is considered smaller than another if it is earlier than the other.
.PP
The datetime a given number of days or seconds later than a given datetime can be found using the addDays() and addSecs() functions. Correspondingly, the number of days or seconds between two times can be found using the daysTo() or secsTo() functions.
.PP
A datetime can also be set using the setTime_t() function, which takes a POSIX-standard "number of seconds since 00:00:00 on January 1, 1970" value.
.PP
The limitations regarding range and resolution mentioned in the QDate and QTime documentation apply for QDateTime also.
.PP
See also QDate and QTime.
.SH MEMBER FUNCTION DOCUMENTATION
.SH "QDateTime::QDateTime ()"
Constructs a null datetime (i.e. null date and null time). A null datetime is invalid, since the date is invalid.
.PP
See also isValid().
.SH "QDateTime::QDateTime ( const QDate & date )"
Constructs a datetime with date \fIdate\fR and null time (00:00:00.000).
.SH "QDateTime::QDateTime ( const QDate & date, const QTime & time )"
Constructs a datetime with date \fIdate\fR and time \fItime.\fR
.SH "QDateTime QDateTime::addDays ( int ndays ) const"
Returns a QDateTime object containing a datetime \fIndays\fR days later than the datetime of this object (or earlier if \fIndays\fR is negative).
.PP
See also daysTo() and addSecs().
.SH "QDateTime QDateTime::addSecs ( int nsecs ) const"
Returns a QDateTime object containing a datetime \fInsecs\fR seconds later than the datetime of this object (or earlier if \fInsecs\fR is negative).
.PP
See also secsTo() and addDays().
.SH "QDateTime QDateTime::currentDateTime () \fC[static]\fR"
Returns the current datetime, as reported by the system clock.
.PP
See also QDate::currentDate() and QTime::currentTime().
.SH "QDate QDateTime::date () const"
Returns the date part of this datetime.
.PP
See also setDate() and time().
.SH "int QDateTime::daysTo ( const QDateTime & dt ) const"
Returns the number of days from this datetime to \fIdt\fR (which is negative if \fIdt\fR is earlier than this datetime).
.PP
See also addDays() and secsTo().
.SH "bool QDateTime::isNull () const"
Returns TRUE if both the date and the time are null. A null date is invalid.
.PP
See also QDate::isNull() and QTime::isNull().
.SH "bool QDateTime::isValid () const"
Returns TRUE if both the date and the time are valid.
.PP
See also QDate::isValid() and QTime::isValid().
.SH "bool QDateTime::operator!= ( const QDateTime & dt ) const"
Returns TRUE if this datetime is different from \fIdt,\fR or FALSE if they are equal.
.PP
See also operator==().
.SH "bool QDateTime::operator< ( const QDateTime & dt ) const"
Returns TRUE if this datetime is earlier than \fIdt,\fR otherwise FALSE.
.SH "bool QDateTime::operator<= ( const QDateTime & dt ) const"
Returns TRUE if this datetime is earlier than or equal to \fIdt,\fR otherwise FALSE.
.SH "bool QDateTime::operator== ( const QDateTime & dt ) const"
Returns TRUE if this datetime is equal to \fIdt,\fR or FALSE if they are different.
.PP
See also operator!=().
.SH "bool QDateTime::operator> ( const QDateTime & dt ) const"
Returns TRUE if this datetime is later than \fIdt,\fR otherwise FALSE.
.SH "bool QDateTime::operator>= ( const QDateTime & dt ) const"
Returns TRUE if this datetime is later than or equal to \fIdt,\fR otherwise FALSE.
.SH "int QDateTime::secsTo ( const QDateTime & dt ) const"
Returns the number of seconds from this datetime to \fIdt\fR (which is negative if \fIdt\fR is earlier than this datetime).
.PP
Example:
.PP
.nf
.br
    QDateTime dt = QDateTime::currentDateTime();
.br
    QDateTime x( QDate(dt.year(),12,24), QTime(17,00) );
.br
    qDebug( "There are %d seconds to Christmas", dt.secsTo(x) );
.fi
.PP
See also addSecs(), daysTo() and QTime::secsTo().
.SH "void QDateTime::setDate ( const QDate & date )"
Sets the date part of this datetime.
.PP
See also date() and setTime().
.SH "void QDateTime::setTime ( const QTime & time )"
Sets the time part of this datetime.
.PP
See also time() and setDate().
.SH "void QDateTime::setTime_t ( uint secsSince1Jan1970UTC )"
Sets the local date and time given the number of seconds that have passed since 00:00:00 on January 1, 1970, Coordinated Universal Time (UTC). On systems that do not support timezones this function will behave as if local time were UTC.
.PP
Note that Microsoft Windows supports only a limited range of values for \fIsecsSince1Jan1970UTC.\fR
.SH "QTime QDateTime::time () const"
Returns the time part of this datetime.
.PP
See also setTime() and date().
.SH "QString QDateTime::toString () const"
Returns the datetime as a string.
.PP
The string format is "Sat May 20 03:40:13 1998".
.PP
This function uses QDate::dayName(), QDate::monthName(), and QTime::toString() to generate the string.
.SH RELATED FUNCTION DOCUMENTATION
.SH "QDataStream & operator<< (QDataStream & s, const QDateTime & dt)"
Writes a datetime to the stream.
.PP
See also Format of the QDataStream operators
.SH "QDataStream & operator>> (QDataStream & s, QDateTime & dt)"
Reads a datetime from the stream.
.PP
See also  Format of the QDataStream operators
.SH "SEE ALSO"
.BR http://doc.trolltech.com/qdatetime.html
.SH COPYRIGHT
Copyright 1992-2000 Trolltech AS, http://www.trolltech.com/.  See the
license file included in the distribution for a complete license
statement.
.SH AUTHOR
Generated automatically from the source code.