datetime.tex

很牛的GUI源码wxWidgets-2.8.0.zip 可在多种平台下运行.

\membersection{Astronomical/historical functions}\label{astronomyhistoryfunctions}

Some degree of support for the date units used in astronomy and/or history is
provided. You can construct a wxDateTime object from a
\helpref{JDN}{wxdatetimesetjdn} and you may also get its JDN,
\helpref{MJD}{wxdatetimegetmodifiedjuliandaynumber} or
\helpref{Rata Die number}{wxdatetimegetratadie} from it.

\helpref{wxDateTime(double jdn)}{wxdatetimewxdatetimejdn}\\
\helpref{Set(double jdn)}{wxdatetimesetjdn}\\
\helpref{GetJulianDayNumber}{wxdatetimegetjuliandaynumber}\\
\helpref{GetJDN}{wxdatetimegetjdn}\\
\helpref{GetModifiedJulianDayNumber}{wxdatetimegetmodifiedjuliandaynumber}\\
\helpref{GetMJD}{wxdatetimegetmjd}\\
\helpref{GetRataDie}{wxdatetimegetratadie}


\membersection{Time zone and DST support}\label{datetimedstzone}

Please see the \helpref{time zone overview}{tdatetimezones} for more
information about time zones. Normally, these functions should be rarely used.

\helpref{FromTimezone}{wxdatetimefromtimezone}\\
\helpref{ToTimezone}{wxdatetimetotimezone}\\
\helpref{MakeTimezone}{wxdatetimemaketimezone}\\
\helpref{MakeFromTimezone}{wxdatetimemakefromtimezone}\\
\helpref{ToUTC}{wxdatetimetoutc}\\
\helpref{MakeUTC}{wxdatetimemakeutc}\\
\helpref{GetBeginDST}{wxdatetimegetbegindst}\\
\helpref{GetEndDST}{wxdatetimegetenddst}\\
\helpref{IsDST}{wxdatetimeisdst}

\helponly{\insertatlevel{2}{

\wxheading{Members}

}}

%%%%%%%%%%%%%%%%%%%%%%%%%%% static functions %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%


\membersection{wxDateTime::ConvertYearToBC}\label{wxdatetimeconvertyeartobc}

\func{static int}{ConvertYearToBC}{\param{int }{year}}

Converts the year in absolute notation (i.e. a number which can be negative,
positive or zero) to the year in BC/AD notation. For the positive years,
nothing is done, but the year 0 is year 1 BC and so for other years there is a
difference of 1.

This function should be used like this:

\begin{verbatim}
    wxDateTime dt(...);
    int y = dt.GetYear();
    printf("The year is %d%s", wxDateTime::ConvertYearToBC(y), y > 0 ? "AD" : "BC");
\end{verbatim}


\membersection{wxDateTime::GetAmPmStrings}\label{wxdatetimegetampmstrings}

\func{static void}{GetAmPmStrings}{\param{wxString *}{am}, \param{wxString *}{pm}}

Returns the translations of the strings {\tt AM} and {\tt PM} used for time
formatting for the current locale. Either of the pointers may be {\tt NULL} if
the corresponding value is not needed.


\membersection{wxDateTime::GetBeginDST}\label{wxdatetimegetbegindst}

\func{static wxDateTime}{GetBeginDST}{\param{int }{year = Inv\_Year}, \param{Country }{country = Country\_Default}}

Get the beginning of DST for the given country in the given year (current one
by default). This function suffers from limitations described in
\helpref{DST overview}{tdatedst}.

\wxheading{See also}

\helpref{GetEndDST}{wxdatetimegetenddst}


\membersection{wxDateTime::GetCountry}\label{wxdatetimegetcountry}

\func{static Country}{GetCountry}{\void}

Returns the current default country. The default country is used for DST
calculations, for example.

\wxheading{See also}

\helpref{SetCountry}{wxdatetimesetcountry}


\membersection{wxDateTime::GetCurrentYear}\label{wxdatetimegetcurrentyear}

\func{static int}{GetCurrentYear}{\param{Calendar }{cal = Gregorian}}

Get the current year in given calendar (only Gregorian is currently supported).


\membersection{wxDateTime::GetCurrentMonth}\label{wxdatetimegetcurrentmonth}

\func{static Month}{GetCurrentMonth}{\param{Calendar }{cal = Gregorian}}

Get the current month in given calendar (only Gregorian is currently supported).


\membersection{wxDateTime::GetCentury}\label{wxdatetimegetcenturystatic}

\func{static int}{GetCentury}{\param{int }{year}}

Get the current century, i.e. first two digits of the year, in given calendar
(only Gregorian is currently supported).


\membersection{wxDateTime::GetEndDST}\label{wxdatetimegetenddst}

\func{static wxDateTime}{GetEndDST}{\param{int }{year = Inv\_Year}, \param{Country }{country = Country\_Default}}

Returns the end of DST for the given country in the given year (current one by
default).

\wxheading{See also}

\helpref{GetBeginDST}{wxdatetimegetbegindst}


\membersection{wxDateTime::GetMonthName}\label{wxdatetimegetmonthname}

\func{static wxString}{GetMonthName}{\param{Month }{month}, \param{NameFlags }{flags = Name\_Full}}

Gets the full (default) or abbreviated (specify {\tt Name\_Abbr} name of the
given month.

\wxheading{See also}

\helpref{GetWeekDayName}{wxdatetimegetweekdayname}


\membersection{wxDateTime::GetNumberOfDays}\label{wxdatetimegetnumberofdays}

\func{static wxDateTime\_t}{GetNumberOfDays}{\param{int }{year}, \param{Calendar }{cal = Gregorian}}

\func{static wxDateTime\_t}{GetNumberOfDays}{\param{Month }{month}, \param{int }{year = Inv\_Year}, \param{Calendar }{cal = Gregorian}}

Returns the number of days in the given year or in the given month of the
year.

The only supported value for {\it cal} parameter is currently {\tt Gregorian}.

\pythonnote{These two methods are named {\tt GetNumberOfDaysInYear}
and {\tt GetNumberOfDaysInMonth} in wxPython.}


\membersection{wxDateTime::GetTimeNow}\label{wxdatetimegettimenow}

\func{static time\_t}{GetTimeNow}{\void}

Returns the current time.


\membersection{wxDateTime::GetTmNow}\label{wxdatetimegettmnow}

\func{static struct tm *}{GetTmNow}{\param{struct tm *}{tm}}

Returns the current time broken down, uses the buffer whose adress is
passed to the function via {\it tm} to store the result.

\membersection{wxDateTime::GetTmNow}

\func{static struct tm *}{GetTmNow}{\void}

Returns the current time broken down. Note that this function returns a
pointer to a static buffer that's reused by calls to this function and
certain C library functions (e.g. localtime). If there is any chance your
code might be used in a multi-threaded application, you really should use
the flavour of function \helpref{wxDateTime::GetTmNow}{wxdatetimegettmnow}
taking a parameter.

\membersection{wxDateTime::GetWeekDayName}\label{wxdatetimegetweekdayname}

\func{static wxString}{GetWeekDayName}{\param{WeekDay }{weekday}, \param{NameFlags }{flags = Name\_Full}}

Gets the full (default) or abbreviated (specify {\tt Name\_Abbr} name of the
given week day.

\wxheading{See also}

\helpref{GetMonthName}{wxdatetimegetmonthname}


\membersection{wxDateTime::IsLeapYear}\label{wxdatetimeisleapyear}

\func{static bool}{IsLeapYear}{\param{int }{year = Inv\_Year}, \param{Calendar }{cal = Gregorian}}

Returns {\tt true} if the {\it year} is a leap one in the specified calendar.

This functions supports Gregorian and Julian calendars.


\membersection{wxDateTime::IsWestEuropeanCountry}\label{wxdatetimeiswesteuropeancountry}

\func{static bool}{IsWestEuropeanCountry}{\param{Country }{country = Country\_Default}}

This function returns {\tt true} if the specified (or default) country is one
of Western European ones. It is used internally by wxDateTime to determine the
DST convention and date and time formatting rules.


\membersection{wxDateTime::IsDSTApplicable}\label{wxdatetimeisdstapplicable}

\func{static bool}{IsDSTApplicable}{\param{int }{year = Inv\_Year}, \param{Country }{country = Country\_Default}}

Returns {\tt true} if DST was used n the given year (the current one by
default) in the given country.


\membersection{wxDateTime::Now}\label{wxdatetimenow}

\func{static wxDateTime}{Now}{\void}

Returns the object corresponding to the current time.

Example:

\begin{verbatim}
    wxDateTime now = wxDateTime::Now();
    printf("Current time in Paris:\t%s\n", now.Format("%c", wxDateTime::CET).c_str());
\end{verbatim}

Note that this function is accurate up to second:
\helpref{wxDateTime::UNow}{wxdatetimeunow} should be used for better precision
(but it is less efficient and might not be available on all platforms).

\wxheading{See also}

\helpref{Today}{wxdatetimetoday}


\membersection{wxDateTime::SetCountry}\label{wxdatetimesetcountry}

\func{static void}{SetCountry}{\param{Country }{country}}

Sets the country to use by default. This setting influences the DST
calculations, date formatting and other things.

The possible values for {\it country} parameter are enumerated in
\helpref{wxDateTime constants section}{wxdatetime}.

\wxheading{See also}

\helpref{GetCountry}{wxdatetimegetcountry}


\membersection{wxDateTime::Today}\label{wxdatetimetoday}

\func{static wxDateTime}{Today}{\void}

Returns the object corresponding to the midnight of the current day (i.e. the
same as \helpref{Now()}{wxdatetimenow}, but the time part is set to $0$).

\wxheading{See also}

\helpref{Now}{wxdatetimenow}


\membersection{wxDateTime::UNow}\label{wxdatetimeunow}

\func{static wxDateTime}{UNow}{\void}

Returns the object corresponding to the current time including the
milliseconds if a function to get time with such precision is available on the
current platform (supported under most Unices and Win32).

\wxheading{See also}

\helpref{Now}{wxdatetimenow}

%%%%%%%%%%%%%%%%%%%%%%%%%%% constructors &c %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%


\membersection{wxDateTime::wxDateTime}\label{wxdatetimewxdatetimedef}

\func{}{wxDateTime}{\void}

Default constructor. Use one of {\tt Set()} functions to initialize the object
later.


\membersection{wxDateTime::wxDateTime}\label{wxdatetimewxdatetimetimet}

\func{wxDateTime\&}{wxDateTime}{\param{time\_t }{timet}}

Same as \helpref{Set}{wxdatetimewxdatetimetimet}.

\pythonnote{This constructor is named {\tt wxDateTimeFromTimeT} in wxPython.}


\membersection{wxDateTime::wxDateTime}\label{wxdatetimewxdatetimetm}

\func{wxDateTime\&}{wxDateTime}{\param{const struct tm\& }{tm}}

Same as \helpref{Set}{wxdatetimewxdatetimetm}

\pythonnote{Unsupported.}


\membersection{wxDateTime::wxDateTime}\label{wxdatetimewxdatetimejdn}

\func{wxDateTime\&}{wxDateTime}{\param{double }{jdn}}

Same as \helpref{Set}{wxdatetimewxdatetimejdn}

\pythonnote{This constructor is named {\tt wxDateTimeFromJDN} in wxPython.}


\membersection{wxDateTime::wxDateTime}\label{wxdatetimewxdatetimetime}

\func{wxDateTime\&}{wxDateTime}{\param{wxDateTime\_t }{hour}, \param{wxDateTime\_t }{minute = 0}, \param{wxDateTime\_t }{second = 0}, \param{wxDateTime\_t }{millisec = 0}}

Same as \helpref{Set}{wxdatetimewxdatetimetime}

\pythonnote{This constructor is named {\tt wxDateTimeFromHMS} in wxPython.}


\membersection{wxDateTime::wxDateTime}\label{wxdatetimewxdatetimedate}

\func{wxDateTime\&}{wxDateTime}{\param{wxDateTime\_t }{day}, \param{Month }{month = Inv\_Month}, \param{int}{ Inv\_Year},
\param{wxDateTime\_t }{hour = 0}, \param{wxDateTime\_t }{minute = 0}, \param{wxDateTime\_t }{second = 0}, \param{wxDateTime\_t }{millisec = 0}}

Same as \helpref{Set}{wxdatetimesetdate}

\pythonnote{This constructor is named {\tt wxDateTimeFromDMY} in wxPython.}


\membersection{wxDateTime::SetToCurrent}\label{wxdatetimesettocurrent}

\func{wxDateTime\&}{SetToCurrent}{\void}

Sets the date and time of to the current values. Same as assigning the result
of \helpref{Now()}{wxdatetimenow} to this object.


\membersection{wxDateTime::Set}\label{wxdatetimesettimet}

\func{wxDateTime\&}{Set}{\param{time\_t }{timet}}

Constructs the object from {\it timet} value holding the number of seconds
since Jan 1, 1970.

\pythonnote{This method is named {\tt SetTimeT} in wxPython.}


\membersection{wxDateTime::Set}\label{wxdatetimesettm}

\func{wxDateTime\&}{Set}{\param{const struct tm\& }{tm}}

Sets the date and time from the broken down representation in the standard
{\tt tm} structure.

\pythonnote{Unsupported.}


\membersection{wxDateTime::Set}\label{wxdatetimesetjdn}

\func{wxDateTime\&}{Set}{\param{double }{jdn}}

Sets the date from the so-called {\it Julian Day Number}.

By definition, the Julian Day Number, usually abbreviated as JDN, of a
particular instant is the fractional number of days since 12 hours Universal
Coordinated Time (Greenwich mean noon) on January 1 of the year -4712 in the
Julian proleptic calendar.

\pythonnote{This method is named {\tt SetJDN} in wxPython.}


\membersection{wxDateTime::Set}\label{wxdatetimesettime}

\func{wxDateTime\&}{Set}{\param{wxDateTime\_t }{hour}, \param{wxDateTime\_t }{minute = 0}, \param{wxDateTime\_t }{second = 0}, \param{wxDateTime\_t }{millisec = 0}}

Sets the date to be equal to \helpref{Today}{wxdatetimetoday} and the time
from supplied parameters.

\pythonnote{This method is named {\tt SetHMS} in wxPython.}


\membersection{wxDateTime::Set}\label{wxdatetimesetdate}