Delphi 常用日期與時(shí)間函數(shù)課件

1、Delphi 常用日期與時(shí)間函數(shù)1 獲取特定的日期與時(shí)間本小節(jié)將為您介紹Delphi 所提供的獲取特定日期與時(shí)間的函數(shù).這些函數(shù)稍后將有詳細(xì)的范例說明.筆者這里將以列表的方式先說明每一個(gè)函數(shù)所代表的意義,如圖示:函數(shù)名稱單元文件所代表的意義NowSysUtils此函數(shù)可返回現(xiàn)在的日期與時(shí)間,其返回值為TDateTime類型DateSysUtils此函數(shù)可返回現(xiàn)在的日期,其返回值為TDateTime類型TimeSysUtils此函數(shù)可返回現(xiàn)在的時(shí)間,其返回值為TDateTime類型TodayDateUtils此函數(shù)可返回今天的日期,其返回值為TDateTime類型,此函數(shù)的結(jié)果與Date函數(shù)相同

2、.TomorrowDateUtils此函數(shù)可返回昨天的日期,其返回值為TDateTime類型YesterdayDateUtils此函數(shù)可返回明天的日期,其返回值為TDateTime類型CurrentyearSysUtils此函數(shù)可返回現(xiàn)在所屬的年度,其返回值為4的整數(shù).例如:2001HoursperdaySysUtils此常數(shù)定義每天的小時(shí)數(shù).HoursPerDay =24;MinsperdaySysUtils此常數(shù)定義每天的分鐘數(shù).MinsPerDay = MinsPerDay*60SecsperdaySysUtils此常數(shù)定義每天的秒數(shù).SecPerDay = MinsPerDay *60

3、msecsperdaySysUtils此常數(shù)定義每天的毫秒數(shù).MSecsPerDay =SecsperDay*1000Now (返回當(dāng)前的日期時(shí)間)引用單元:SysUtils函數(shù)聲明:Function Now : TDateTime;范例D-1Procedure TForm1.Button1Click(Sender: TObject);VarMyDateTime : TDateTime;beginMyDateTime :=Now; Showmessage(DateTimeToStr(MyDateTime);end;Date(返回當(dāng)前的日期)引用單元:SysUtils函數(shù)聲明:Function

4、Day :TDateTime;范例D-2Procedure TForm1.Button1Click(Sender: TObject);VarMyDateTime : TDateTime;beginMyDateTime :=Date; Showmessage(DateTimeToStr(MyDateTime);end;Time(返回當(dāng)前的時(shí)間)引用單元:SysUtils函數(shù)聲明:Function Time:TDateTime;范例D-3Procedure TForm1.Button1Click(Sender: TObject);VarMyDateTime : TDateTime;beginMyD

5、ateTime :=Time; Showmessage(DateTimeToStr(MyDateTime);end;Today(返回今天的日期)引用單元:DateUtils函數(shù)聲明:Function Today :TDateTime;范例D-4Procedure TForm1.Button1Click(Sender: TObject);VarMyDateTime : TDateTime;Begin/uses DateUtilsMyDateTime :=Today; Showmessage(DateTimeToStr(MyDateTime);end;Tomorrow(返回明天的日期)引用單元:D

6、ateUtils函數(shù)聲明:Function Tomorrow:TDateTime;范例D-5Procedure TForm1.Button1Click(Sender: TObject);VarMyDateTime : TDateTime;Begin/uses DateUtilsMyDateTime :=Tomorrow; /MyDateTime : Now +1; /兩者相同Showmessage(DateTimeToStr(MyDateTime); /不包含時(shí)間部分end;Yesterday(返回昨天的日期)引用單元:DateUtils函數(shù)聲明:Function Yesterday :TDa

7、teTime;范例D-6Procedure TForm1.Button1Click(Sender: TObject);VarMyDateTime : TDateTime;Begin/uses DateUtilsMyDateTime :=Yesterday; /MyDateTime : Now -1; /兩者相同Showmessage(DateTimeToStr(MyDateTime); /不包含時(shí)間部分end;CurrentYear(返回現(xiàn)在所屬的年度)引用單元:SysUtils函數(shù)聲明:Function CurrentYear :Word;范例D-7Procedure TForm1.Butt

8、on1Click(Sender: TObject);VarThisYear: Word;Beginthis year := CurrentYear;Showmessage(IntToStr(ThisYear); / 4位整數(shù)end;HoursPerDay,MinsPerDay,SecsPerDay及MsecsPerDay等日期與時(shí)間常數(shù).引用單元:SysUtils函數(shù)聲明:Function CurrentYear:Word;范例D-8Procedure TForm1.Button1Click(Sender: TObject);BeginShowmessage(每天的小時(shí)數(shù)= + IntToSt

9、r(HoursperDay); /24 Showmessage(每天的分鐘數(shù)= + IntToStr(MinsperDay); / 1440Showmessage(每天的秒數(shù)= + IntToStr(SecsperDay); /24 Showmessage(每天的毫秒數(shù)= + IntToStr(MSecsperDay); /24 end;D.2 日期處理函數(shù):函數(shù)名稱單元文件所代表的意義YearOfDateUtils此函數(shù)可獲取TDateTime格式中的年度,其返回值為Word類型.YearsBeTweenDateUtils此函數(shù)可返回兩個(gè)指定日期間的年份,一年以365.25天為計(jì)算單位.其返

10、回值不包含小數(shù)部分YearSpanDateUtils此函數(shù)可返回兩個(gè)指定日期間的年份,一年以365.25天為計(jì)算單位.其返回值包含小數(shù)部分StartOfAYearDateUtils此函數(shù)可返回特定年份的第一天EndOfAYearDateUtils此函數(shù)可返回特定年份的最后一天StrtOfTheYearDateUtils此函數(shù)可返回特定日期的該年第一天EndOfTheYearDateUtils此函數(shù)可返回特定日期的該年最后一天IncYearDateUtils此函數(shù)可將指定的TDateTime變量加上指定的年度,其默認(rèn)值為1年MonthOfDateUtils此函數(shù)可獲取TDateTime格式中的月

11、份,其返回值為Word類型MonthOfTheYearDateUtils此函數(shù)可獲取TDateTime格式中的月份,其返回值為Word類型MonthBetweenDateUtils次函數(shù)可返回兩個(gè)指定日期間的月份數(shù),一個(gè)月以30.4375天為計(jì)算單位.其返回值不包含小數(shù)部分MonthSpanDateUtils次函數(shù)可返回兩個(gè)指定日期間的月份數(shù),一個(gè)月以30.4375天為計(jì)算單位.其返回值包含小數(shù)部分StartOfAMonthDateUtils此函數(shù)可返回特定年月的第一天EndOfAMonthDateUtils此函數(shù)可返回特定年月的最后一天StartOfTheMonthDateUtils此函數(shù)可

12、返回指定日期的該年的第一天EndOfTheMonthDateUtils此函數(shù)可返回指定日期的該年的最后一天IncMonthDateUtils此函數(shù)可將指定的TDateTime變量加上指定的月份,其默認(rèn)值為加上1個(gè)月IncAMonthDateUtils此函數(shù)可將指定的年月日加上指定的月份,其默認(rèn)值為加上1個(gè)月DaysInAYearDateUtils此函數(shù)可返回指定年份的總天數(shù)DaysInYearDateUtils此函數(shù)可返回指定TDateTime變量中該年分的總天數(shù)DaysInAMonthDateUtils此函數(shù)可返回指定月份的總天數(shù)DaysInMonthDateUtils此函數(shù)可返回指定TDa

13、teTime變量中該月份的總天數(shù)DaysOfDateUtils此函數(shù)可獲取TDateTime格式中的日期,其返回值為Word類型DaysBetweenDateUtils此函數(shù)可獲取格式中的日期,其返回值不包含小數(shù)部分DaySpanDateUtils此函數(shù)可返回兩個(gè)指定日期間的天數(shù),其返回值包含小數(shù)部分DayOfTheYearDateUtils此函數(shù)可返回指定TDateTime變量為該年的第幾天.例如2月1日則返回32DayOfTheMonthDateUtils此函數(shù)可返回指定TDateTime變量為該月的第幾天,其返回值介于1到31DayOfTheWeekDateUtils此函數(shù)可返回指定TD

14、ateTime變量為該周的第幾天,其返回值介于1到7.星期一為第一天.DayOfWeekDateUtils此函數(shù)可返回指定TDateTime變量為該周的第幾天,其返回值介于1到7.星期日為第一天.StartOfADayDateUtils此函數(shù)可返回指定日期一天的開始時(shí)間,其返回值為TDateTime類型.其時(shí)間默認(rèn)為12:00:000 AMEndOfADayDateUtils此函數(shù)可返回指定日期一天的結(jié)束時(shí)間,其返回值為TDateTime類型.其時(shí)間默認(rèn)為11:59:999 PMStartOfTheDayDateUtils此函數(shù)可返回指定TDateTime變量的一天開始時(shí)間,其返回值為TDat

15、eTime類型.其時(shí)間默認(rèn)為:12:00:000 AMEndOfTheDayDateUtils此函數(shù)可返回指定TDateTime變量的一天結(jié)束時(shí)間,其返回值為TDateTime類型.其時(shí)間默認(rèn)為11:59:999PMIncDayDateUtils此函數(shù)可為指定日期加上特定的天數(shù),其返回值為TDateTime類型,其默認(rèn)天數(shù)為1天WeeksInAYearDateUtils此函數(shù)可返回指定年度的周數(shù),其返回值不是52就是53WeeksInYearDateUtils此函數(shù)可返回指定TDateTime變量的周數(shù),其返回值不是52就是53WeekOfDateUtils次函數(shù)可返回指定日期為該年的第幾周,

16、其返回值為153WeekOfTheYearDateUtils次函數(shù)可返回指定日期為該年的第幾周,其返回值為153WeekOfTheMonthDateUtils次函數(shù)可返回指定日期為該月的第幾周,其返回值為16WeeksBetweenDateUtils此函數(shù)可返回兩個(gè)指定日期間的周數(shù),其返回值不包含小數(shù)部分WeekSpanDateUtils此函數(shù)可返回兩個(gè)指定日期間的周數(shù),其返回值包含小數(shù)部分StartOfAweekDateUtils此函數(shù)可返回指定日期一周的開始時(shí)間,其返回值為TDateTime類型.其時(shí)間默認(rèn)為12:00:000 PMEndOfAWeekDateUtils此函數(shù)可返回指定日期

17、一周的結(jié)束時(shí)間,其返回值為TDateTime類型.其時(shí)間默認(rèn)為11:59:999 PMStartOfTheWeekDateUtils此函數(shù)可返回指定TDateTime變量的一周開始時(shí)間,其返回值為TDateTime類型.其其時(shí)間默認(rèn)為12:00:000 AMEndOfTheWeekDateUtils此函數(shù)可返回指定TDateTime變量的一周結(jié)束時(shí)間,其返回值為TDateTime類型.其時(shí)間默認(rèn)為11:59:999 AMIncWeekDateUtils此函數(shù)可將指定日期加上指定周數(shù),其返回值為TDateTime類型YearOf(返回指定日期的年度)引用單元:DateUtils函數(shù)聲明:Func

18、tion YearOf ( const AValue : TDateTime) :Word;范例D-9Procedure TForm1.Button1Click(Sender: TObject);Begin/三者都相同Showmessage(年度= + IntToStr(YearOf(Now); Showmessage(年度= + IntToStr(YearOf(Date); Showmessage(年度= + IntToStr(YearOf(Today); end;YearsBetween(返回兩個(gè)指定日期間的年份)引用單元:DateUtils函數(shù)聲明:Function YearsBetwe

19、en ( const ANow, AThen : TDateTime) :Integer;范例D-10Procedure TForm1.Button1Click(Sender: TObject);Begin/不包含小數(shù),一年以365.25天為計(jì)算單位Showmessage(幾年= + IntToStr(YearsBetween(Now,Now+560); /1end;YearSpan(返回兩個(gè)指定日期間的年份)引用單元:DateUtils函數(shù)聲明:Function YearsSpan( const ANow , AThen : TDateTime) :Double;范例D-11Procedur

20、e TForm1.Button1Click(Sender: TObject);Begin/包含小數(shù),一年以365.25天為計(jì)算單位Showmessage(幾年= + FloatToStr(YearSpan(Now,Now+560);/1.53.end;StartOfAYear(返回特定年份的第一天)引用單元:DateUtils函數(shù)聲明:Function StartOfAYear ( const AYear) : TDateTime;范例D-12Procedure TForm1.Button1Click(Sender: TObject);BeginShowmessage(DateTimeToSt

21、r(StartOfAYear(2001);/2001/1/1 早上12:00:00end;EndOfAYear(返回特定年份的最后一天)引用單元:DateUtils函數(shù)聲明:Function EndOfAYear ( const AYear) : TDateTime;范例D-13Procedure TForm1.Button1Click(Sender: TObject);BeginShowmessage(DateTimeToStr(EndOfAYear(2001);/2001/12/31 下午11:59:59end;StartOfTheYear(返回指定日期的該年的第一天)引用單元:DateU

22、tils函數(shù)聲明:Function StartOfTheYear ( const AValue : TDateTime) :TDateTime;范例D-14Procedure TForm1.Button1Click(Sender: TObject);BeginShowmessage(DateTimeToStr(StarOfTheYear(Now);/指定的年度/1/1早上12:00:00end;EndOfTheYear(返回指定日期的該年的最后一天)引用單元:DateUtils函數(shù)聲明:Function EndOfTheYear ( const AValue : TDateTime) :TDa

23、teTime;范例D-15Procedure TForm1.Button1Click(Sender: TObject);BeginShowmessage(DateTimeToStr(StarOfTheYear(Now);/指定年度/12/31下午11:59:59end;IncYear(將指定的TDateTime變量加上指定的年)引用單元:DateUtils函數(shù)聲明:Function IncYear ( const AValue : TDateTimel; const ANumberOfYears : Integer =1) :TDateTime;范例D-16 Procedure TForm1.

24、Button1Click(Sender: TObject);varmyDateTime : TDateTime;BeginmyDateTime : = IncYear(Now,3); /往后加3年Showmessage(DateTimeToStr(myDateTime);End;MonthOf(獲取TDateTime格式中的月份)引用單元:DateUtils函數(shù)聲明:Function MonthOf ( const AValue : TDateTime) :Word;范例D-17 Procedure TForm1.Button1Click(Sender: TObject);varmyDateT

25、ime : TDateTime;m : Integer;BeginmyDateTime : = Now; /兩個(gè)函數(shù)獲取相同的結(jié)果m := MonthofTheYear(myDateTime);Showmessage(IntToStr(m);end;MonthOfTheYear(獲取TDateTime格式中的月份)引用單元:DateUtils函數(shù)聲明:Function MonthOfTheYear ( const AValue : TDateTime) :Word;范例D-18 Procedure TForm1.Button1Click(Sender: TObject);vari :Integ

26、er;f :Double;Begini := MonthsBetween(Now,Now+89);/差89天Showmessage(IntToStr(i);/2f := MonthSpan(Now,Now+89);/差89天Showmessage(FloatToStr(f);/2.924End;MonthsBetween(返回兩個(gè)指定日期間的月份數(shù))引用單元:DateUtils函數(shù)聲明:Function MonthsBetween ( const ANow, AThen : TDateTime) :Integer;MonthSpan(返回兩個(gè)指定日期間的月份數(shù))引用單元:DateUtils函數(shù)

27、聲明:Function MonthSpan ( const ANow, AThen : TDateTime) :Double;StartOfAMonth(返回特定年月的第一天)引用單元:DateUtils函數(shù)聲明:Function StartOfAMonth ( const AYear, AMonth : Word) : TDateTime;EndOfAMonth(返回特定年月的最后一天)引用單元:DateUtils函數(shù)聲明:Function EndOfTheMonth ( const AYear, AMonth : Word) : TDateTime;StartOfTheMonth(返回特定

28、年月的第一天)引用單元:DateUtils函數(shù)聲明:Function StartOfTheMonth ( const AValue : TDateTime) :TDateTime;EndOfTheMonth(返回特定年月的最后一天)引用單元:DateUtils函數(shù)聲明:Function EndOfTheMonth ( const AValue : TDateTime) :TDateTime;范例D-19varmyDateTime :TDateTime;Year,Month :Integer;BeginYear := YearOf(Now);Month :=MonthOf(Now);/找出當(dāng)前月

29、份的第一天myDateTime := StartOfAMonth(Year,Month);Showmessage(DateTimeToStr(myDateTime);/找出當(dāng)前月份的最后一天myDateTime := EndOfAMonth(Year,Month);Showmessage(DateTimeToStr(myDateTime);/找出當(dāng)前月份的第一天myDateTime := StartOfTheMonth(Now);Showmessage(DateTimeToStr(myDateTime);/找出當(dāng)前月份的最后一天myDateTime := EndOfTheMonth(Now);

30、Showmessage(DateTimeToStr(myDateTime);end;IncMonth(指定的TDateTime變量加上指定的月份)引用單元:DateUtils函數(shù)聲明:Function IncMonth ( const Date : TDateTime ; NumberOfMonths : Integer = 1) :TDateTime;IncAMonth(指定的年月日變量加上指定的月份)引用單元:DateUtils函數(shù)聲明:Procedure IncAMonth ( Var Year, Month , Day : Word ; NumberOfMonths : Integer

31、 =1 );范例D-20varmyDateTime :TDateTime;Year,Month,Day :Word;Begin/加上指定的月份myDateTime := IncMonth(Now,3);/加上三個(gè)月Showmessage(DateTimeToStr(myDateTime);Year := YearOf(Now);Day := Dayof(Now);/加上指定的月份IncAMonth(Year,Month,Day,3);Showmessage(Month+IntToStr(Month);end ;DaysInAYear(返回指定年份的總天數(shù))引用單元:DateUtils函數(shù)聲明:

32、Function DaysInAYear ( const AYear : Word) :Word;DaysInYear(返回指定TDateTime變量中該年份的總天數(shù))引用單元:DateUtils函數(shù)聲明:Function MinuteOfTheHour ( const AValue : TDateTime) :Word;DaysInAMonth(返回指定月份的總天數(shù))引用單元:DateUtils函數(shù)聲明:Function DaysInAMonth ( const AYear , AMonth : Word) :Word;DaysInMonth(返回指定TDateTime變量中該月份的總天數(shù))

33、引用單元:DateUtils函數(shù)聲明:Function DaysInMonth ( const AValue : TDateTime) :Word;范例D-21procedure TForm1.Button1Click(Sender : TObfect) ;varmyDateTime : TDateTime ;Year, Month : Word ;I : Integer ;BeginYear := YearOf(Now) ;/獲取指定年份的總天數(shù)i := DaysInAYear(Year) ;Showmessage(DaysInAYear=+IntToStr (i) ;i := DaysIn

34、Year(now) ;Showmessage(DaysInMonth = + IntToStr (i) ;/獲取指定月份的總天數(shù)Month := MonthOf(Now) ;i := DaysInMonth(Now) ;Showmessage( DaysInMonth = +IntToStr(i) ;end;DaysOf(獲取TDateTime格式中的日期)引用單元:DateUtils函數(shù)聲明:Function DaysOf ( const AValue : TDateTime) :Word;范例D-22procedure TForm1.Button1Click(Sender : TObfec

35、t) ;varDay : Word ;begin/獲取指定TDateTime的日期Day := DayOf(Now) ;Showmessage(IntToStr(Day) ;end ;DaysBetween(返回兩個(gè)指定日期間的天數(shù))引用單元:DateUtils函數(shù)聲明:Function DaysBetween( const ANow, AThen : TDateTime) :Integer;DaySpan(返回兩個(gè)指定日期間的天數(shù))引用單元:DateUtils函數(shù)聲明:Function DaySpan ( const ANow , AThen : TDateTime) :Double;范例D

36、-23vari : Integer ;f : Double ;begin/獲取兩個(gè)日期的天數(shù)f:=DaySpan(Now-100 , Now) ;i := DaysBetween(Now-100 , Now) ;Showmessage(intToStr(i) ; /100Showmessage(FloatToStr(f) ; /100 end ;DayOfTheYear(返回指定TDateTime變量為該年的第幾天)引用單元:DateUtils函數(shù)聲明:Function DayOfTheYear ( const AValue : TDateTime) :Word;DayOfTheMonth(返

37、回指定TDateTime變量為該月的第幾天)引用單元:DateUtils函數(shù)聲明:Function DayOfTheMonth ( const AValue : TDateTime) :Word;DayOfTheWeek(返回指定TDateTime變量為該周的第幾天)引用單元:DateUtils函數(shù)聲明:Function DayOfTheWeek ( const AValue : TDateTime) :Word;DayOfWeek(返回指定TDateTime變量為該周的第幾天)引用單元:DateUtils函數(shù)聲明:Function DayOfWeek ( Date : TDateTime)

38、:Integer;范例D-24procedure TForm1.Button1Click(Sender : TObfect) ;vari : Integer ;begin/返回指定TDateTime為該年的第幾天i := DayOfTheYear(Now) ;Showmessage(IntToStr(i) ;/返回指定TDateTime為該月的第幾天i := DayOfTheMonth(Now) ;Showmessage(IntToStr(i) ;/返回指定TDateTime為該周的第幾天(星期一為第一天)i := DayOfTheWeek(Now) ;Showmessage(IntToStr

39、(i) ;end ;StartOfADay(返回指定日期一天的開始)引用單元:DateUtils函數(shù)聲明:Function StartOfADay ( const AYear , AMonth, ADay : Word) :TDateTime;Function StartOfADay ( const AYear , ADayOfYear : Word) :TDateTime;范例D-25procedure TForm1.Button1Click(Sender : TObfect) ;vartmpDateTime : TDateTime ;AYear , ADayOfYear , AMonth

40、, ADay :Word ;beginAYear := 2001 ; /指定年度ADayOfYear := 32 ;./第32天tmpDateTime :=StartOfADay(AYear , ADayOfYear) ;Showmessage(DateTimeToStr(tmpDateTime) ; /2001/02/01AMonth := 1 ;ADay := 32 ; /從AMonth第一天起第32天TmpDateTime := StartOfADay(AYear , AMonth , ADay) ;Showmessage(DateTimeToStr(tmpDateTime) ; /20

41、01/02/01end ;EndOfADay(返回指定日期一天的結(jié)束時(shí)間)引用單元:DateUtils函數(shù)聲明:Function EndOfADay ( const AYear, AMonth,ADay : Word) : TDateTime;Function EndOfADay ( const AYear, ADayOfYear : Word) : TDateTime;范例D-26procedure TForm1.Button1Click(Sender : TObfect) ;vartmpDateTime : TDateTime ;AYear , ADayOfYear , AMonth ,

42、ADay : Word ;beginAYear := 2001 ; /指定年度ADayOfYear := 32 ; /第32天tmpDateTime := EndOfADay(AYear , AMonth , ADay) ;Showmessage(DateTimeToStr(tmpDateTime) ;/2001/02/01 PM 11:59:59end ;StartOfTheDay(返回指定TDateTime變量的一天開始時(shí)間)引用單元:DateUtils函數(shù)聲明:Function StartToTheDay ( const AValue : TDateTime) :TDateTime;En

43、dOfTheDay(返回指定TDateTime變量的一天結(jié)束時(shí)間)引用單元:DateUtils函數(shù)聲明:Function EndOfTheDay ( const AValue : TDateTime) : TDateTime;范例D-27procedure TForm1.Button1Click(Sender : TObfect) ;vartmpDateTime : TDateTime ;begintmpDateTime := StartOfTheDay(Now) ;Showmessage(DateTimeToStr(tmpDateTime) ;/YYYY/MM/DD AM 12:00:00t

44、mpDateTime := EndOfTheDay(Now) ;Showmessage(DateTo /YYYY/MM/DD PM 11:59:59end ;IncDay(可為指定日期加上特定的天數(shù))引用單元:DateUtils函數(shù)聲明:Function IncDay ( const AValue : TDateTime ; const ANumberOfDays : Integer =1) :TDateTime;范例D-28procedure TForm1.Button1Click(Sender : TObfect) ;vartmpDateTime : TDateTime ;begintmp

45、DateTime := Incday(Now,5) ;Showmessage(DateTimeToStr(tmpDateTime) ;/時(shí)間部分并不會(huì)改變end ;WeeksInAYear(返回指定年度的周數(shù))引用單元:DateUtils函數(shù)聲明:Function WeeksInAYear( const AYear : Word) :Word;WeeksInYear(返回指定TDateTime變量的周數(shù))引用單元:DateUtils函數(shù)聲明:Function WeeksInYear ( const AValue : TDateTime) :Word;范例D-29procedure TForm1

46、.Button1Click(Sender : TObfect) ;varweeks : word ;beginweeks :=weeksInAYear(2001) ;Showmessage(IntToStr(weeks) ; /52Weeks := WeeksInYear(Now) ;Showmessage(IntToStr(weeks) ; /52end ;WeeksOf(返回指定日期為該年的第幾周)引用單元:DateUtils函數(shù)聲明:Function WeekOf ( const AValue : TDateTime) :Word;WeekOfTheYear(返回指定日期為該年的第幾周)

47、引用單元:DateUtils函數(shù)聲明:Function WeekOfTheYear ( const AValue : TDateTime) :Word;WeekOfTheMonth(返回指定日期為該月的第幾周)引用單元:DateUtils函數(shù)聲明:Function WeekOfTheMonth ( const AValue : TDateTime) :Word;范例D-30Procedure TForm1.Button1Click(Sender: TObject);VarI : Word;BeginI :=WeekOf(Now);Showmessage(weekof= + IntToStr(i

48、); i := WeekOfTheYear(Now );Showmessage(WeekOfTheYear = + IntToStr(i);I := WeekOfTheMonth(Now);Showmessage(WeekOfTheMonth= + IntToStr(i); end;WeeksBetween(返回兩個(gè)指定日期間的周數(shù))引用單元:DateUtils函數(shù)聲明:Function WeeksBetween ( const ANow , AThen, : TDateTime) :Integer;WeekSpan(返回兩個(gè)指定日期間的周數(shù))引用單元:DateUtils函數(shù)聲明:Functi

49、on WeekSpan( const ANow ,AThen : TDateTime) :Double;范例D-31Procedure TForm1.Button1Click(Sender: TObject);VarI : Integer;F :Double;BeginI :=WeeksBetween(Now , Now + 29);Showmessage(InttoStr(i); /4F := WeekSpan(Now , Now + 29);Showmessage(FloatToStr(f); /4.14end;StartOfAWeek(返回指定日期一周的開始時(shí)間)引用單元:DateUti

50、ls函數(shù)聲明:Function StartOfAWeek ( const AYear , AWeekOfYear : Word; const ADayOfWeek : Word = 1) : TDateTime;EndOfAWeek(返回指定日期一周的結(jié)束時(shí)間)引用單元:DateUtils函數(shù)聲明:Function EndOfAWeek ( const AYear , AWeekOfYear : Word; const ADayOfWeek : Word = 7) : TDateTime;范例D-32Procedure TForm1.Button1Click(Sender: TObject);

51、VartempDateTime: TDateTime;AYear , AWeekOfYear , ADayOfWeek : Word;BeginAYear := 2001;AWeekOfYear :=2; /第二周ADayOfWeek :=1; /第一天tempDateTime := StartofAweek(AYear, AWeekOfYear, ADayOfWeek);/2001/01/08 AM 12:00:00:00showmessage(DateTimeToStr(tempDateTime);/AYearf := 2001;/AWeekofYear :=2; /第二周ADayOfWe

52、ek : =7 ;/ 第七天tempDatetime := EndOfAWeek(AYear, AWeekOfYear, AdayOfWeek);/2001/01/14 Pm 11:59:59Showmessage(DateTimeToStr(tempDateTime); /4.14end;StartOfTheWeek(返回指定日期一周的開始時(shí)間)引用單元:DateUtils函數(shù)聲明:Function StartOfTheWeek ( const AValue : TDateTime) :TDateTime;EndOfTheWeek(返回指定日期一周的結(jié)束時(shí)間)引用單元:DateUtils函數(shù)

53、聲明:Function EndOfTheWeek ( const AValue : TDateTime) :TDateTime;范例D-33Procedure TForm1.Button1Click(Sender: TObject);VartempDateTime : TDateTime;begintempDateTime :=StartOfTheWeek(Now);/YYYY / MM / DD AM 12:00:00:00Showmessage(DateTimeToStr(tempDateTime);tempDateTime := EndOfTheWeek(Now);/YYYY / MM

54、/ DD + 6 PM 11:59 :59Showmessage(DateTimeToStr(tempDateTime);end;IncWeek(將指定日期加上指定周數(shù))引用單元:DateUtils函數(shù)聲明:Function IncWeek ( const AValue : TDateTime; const ANumberOfWeeks : Integer = 1) :TDateTime;范例D-34:Procedure TForm1.Button1Click(Sender: TObject);VartempDateTime : TDateTime;begintempDateTime :=IncWeek(Now , 5); /加上5周Showmessage(DateTimeToStr(tempDateTime);end;D.3 時(shí)間處理函數(shù)函數(shù)名稱單元文件所代表的意義HoursBetweenDateUtils此函數(shù)可返回兩個(gè)指定TDateTime變量間的小時(shí)數(shù),返回值不包含小數(shù)部分.HourSpanDateUtils此函數(shù)可返回兩個(gè)指定TDateTime變量間