delphi7.0如何使用时间函数

Question

如题所述

Answer 1

Date 传回目前的日期
Unit SysUtils
函数原型 function Date: TDateTime;
范例 procedure TForm1.Button1Click(Sender: TObject);
begin
Label1.Caption := 'Today is ' + DateToStr(Date);
end;
------------------------------------------
DateTimeToStr 日期时间转换成内定型字串(1996/12/20 09:12:20 PM)
------------------------------------------
Unit SysUtils
函数原型 function DateTimeToStr(DateTime: TDateTime): string;
范例 procedure TForm1.Button1Click(Sender: TObject);
begin
Label1.Caption := DateTimeToStr(Now);
end;
--------------------------------------------------------
DateTimeToString 日期时间转换成自定型字串
-------------------------------------------------------
Unit SysUtils
函数原型 procedure DateTimeToString(var Result: string; const Format:
string; DateTime: TDateTime);
范例 procedure TForm1.FormCreate(Sender: TObject);
var
s:string;
begin
DateTimeToString(s,'dddd,mmmm d,yyyy "at" hh:mm
AM/PM',Now);
Label1.Caption :=s;
end;
结果 星期五,十二月 20,1996 at 09:20 PM
-----------------------------------------------------------------------------
**** Format格式叁考下面.FormatDateTime.
--------------------------------------------------------
DateToStr 日期转换成内定型字串.(1996/12/20)
--------------------------------------------------------
Unit SysUtils
函数原型 function DateToStr(Date: TDateTime): string;
范例
procedure TForm1.Button1Click(Sender: TObject);
begin
Label1.Caption := 'Today is ' + DateToStr(Date);
end;
# Date, DateToStr Example
--------------------------------------------------------
DayOfWeek 求叁数日期是星期几.
--------------------------------------------------------
Unit SysUtils
函数原型 function DayOfWeek(Date: TDateTime): Integer;
说明 传回值是一整数,1~7.
星期日为1.
范例
procedure TForm1.Button1Click(Sender: TObject);
var
ADate: TDateTime;
days: array[1..7] of string;
begin
days[1] := 'Sunday';
days[2] := 'Monday';
days[3] := 'Tuesday';
days[4] := 'Wednesday';
days[5] := 'Thursday';
days[6] := 'Friday';
days[7] := 'Saturday';
ADate := StrToDate(Edit1.Text);
ShowMessage(Edit1.Text + ' is a ' + days[DayOfWeek(ADate)];
end;
# StrToDate, DayOfWeek Example
--------------------------------------------------------
DecodeDate 将TDateTime型态的日期变数，转为Word型态.
--------------------------------------------------------
范例
procedure TForm1.Button1Click(Sender: TObject);
var
Present: TDateTime;
Year, Month, Day, Hour, Min, Sec, MSec: Word;
begin
Present:= Now;
DecodeDate(Present, Year, Month, Day);
Label1.Caption := 'Today is Day ' + IntToStr(Day) + ' of Month '
+ IntToStr(Month) + ' of Year ' + IntToStr(Year);
DecodeTime(Present, Hour, Min, Sec, MSec);
Label2.Caption := 'The time is Minute ' + IntToStr(Min) + ' of Hour '
+ IntToStr(Hour);
end;
# DecodeDate, DecodeTime Example
--------------------------------------------------------
DecodeTime 将TDateTime型态的时间变数，转为Word型态.
--------------------------------------------------------
Unit SysUtils
函数原型 procedure DecodeDate(Date: TDateTime; var Year, Month,Day: Word);
函数原型 procedure DecodeTime(Time: TDateTime; var Hour, Min, Sec,MSec: Word);
范例 procedure TForm1.Button1Click(Sender: TObject);
var
Present: TDateTime;
Year, Month, Day, Hour, Min, Sec, MSec: Word;
begin
Present:= Now;
DecodeDate(Present, Year, Month, Day);
Label1.Caption := 'Today is Day ' + IntToStr(Day) + ' of
Month ' + IntToStr(Month) + ' of Year ' + IntToStr(Year);
DecodeTime(Present, Hour, Min, Sec, MSec);
Label2.Caption := 'The time is Minute ' +IntToStr(Min) + ' of
Hour ' + IntToStr(Hour);
end;
--------------------------------------------------------
EncodeDate 将Word型态的日期变数，转为TDateTime型态.
--------------------------------------------------------
范例
procedure TForm1.Button1Click(Sender: TObject);
var
MyDate: TDateTime;
begin
MyDate := EncodeDate(StrToInt(Edit1.Text), StrToInt(Edit2.Text), StrToInt(Edit3.Text));
Label1.Caption := DateToStr(MyDate);
end;
-------------------------------------------------------
EncodeTime 将Word型态的时间变数，转为TDateTime型态.
--------------------------------------------------------
Unit SysUtils
函数原型 function EncodeDate(Year, Month, Day: Word): TDateTime;
函数原型 function EncodeTime(Hour, Min, Sec, MSec: Word):
TDateTime;
范例 procedure TForm1.Button1Click(Sender: TObject);
var
MyDate: TDateTime;
MyTime: TDateTime;
begin
MyDate := EncodeDate(83, 12, 31);
Label1.Caption := DateToStr(MyDate);
MyTime := EncodeTime(0, 45, 45, 7);
Label2.Caption := TimeToStr(MyTime);
end;
范例
procedure TForm1.Button1Click(Sender: TObject);
var
MyTime: TDateTime;
begin
MyTime := EncodeTime(0, 45, 45, 7);
Label1.Caption := TimeToStr(MyTime);
end;
--------------------------------------------------------
FormatDateTime 将日期时间依Format的格式转换给一字串.
--------------------------------------------------------
Unit SysUtils
函数原型 function FormatDateTime(const Format: string; DateTime:
TDateTime): string;
**** 类似DateTimeToString.
Format格式
c 内定值ShortDateFormat的格式.(1996/12/20 09:20:15 PM).
d 日期,前面不补0.(1-31)
dd 日期,前面补0.(01-31)
ddd 星期.(星期日).
Dddd 中文2.01版,同上.
ddddd 日期.(1996/12/20)
dddddd 日期.(1996年12月20日)
m 月份,前面不补0.(1-12)
mm 月份,前面补0.(01-12)
mmm 中文显示.(十二月)
mmmm 中文2.01版,同上.
Yy 年度.(00-99)
yyyy 年度.(0000-9999)
h 小时.(0-23)
hh 小时.(00-23)
n 分钟.(0-59)
nn 分钟.(00-59)
s 秒钟.(0-59)
ss 秒钟.(00-59)
t 时间.(09:20 PM)
tt 时间.(09:20:15 PM)
am/pm 单独显示am or pm.(若大写,则显示大写)
a/p 单独显示a or p.
范例
The following example assigns 'The meeting is on Wednesday, February 15, 1995 at 10:30 AM' to the string variable S.
S := FormatDateTime('"The meeting is on " dddd, mmmm d, yyyy, " at " hh:mm AM/PM',
StrToDateTime('2/15/95 10:30am'));//???
--------------------------------------------------------
Now 传回目前的日期时间.
--------------------------------------------------------
Unit SysUtils
函数原型 function Now: TDateTime;
范例
procedure TForm1.Button1Click(Sender: TObject);
begin
Label1.Caption := DateTimeToStr(Now);
end;
# Now, DateTimeToStr Example
--------------------------------------------------------
StrToDate 将字串转为TDateTime型态的日期.
--------------------------------------------------------
Unit SysUtils
函数原型 function StrToDate(const S: string): TDateTime;
范例 procedure TForm1.Button1Click(Sender: TObject);
var
ADate: TDateTime;
begin
ADate := StrToDate(Edit1.Text);
Label1.Caption := DateToStr(ADate);
end;
范例
procedure TForm1.Button1Click(Sender: TObject);
var
ADate: TDateTime;
days: array[1..7] of string;
begin
days[1] := 'Sunday';
days[2] := 'Monday';
days[3] := 'Tuesday';
days[4] := 'Wednesday';
days[5] := 'Thursday';
days[6] := 'Friday';
days[7] := 'Saturday';
ADate := StrToDate(Edit1.Text);
ShowMessage(Edit1.Text + ' is a ' + days[DayOfWeek(ADate)];
end;
# StrToDate, DayOfWeek Example
--------------------------------------------------------
StrToDateTime 将字串转为TDateTime型态的日期时间.
--------------------------------------------------------
Unit SysUtils
函数原型 function StrToDateTime(const S: string): TDateTime;
范例
procedure TForm1.Button1Click(Sender: TObject);
var
ADateAndTime: TDateTime;
begin
ADateAndTime := StrToDateTime(Edit1.Text);
Table1.FieldByName('TimeStamp').AsDateTime := ADateAndTime;
end;
--------------------------------------------------------
StrToTime 将字串转为TDateTime型态的时间.
--------------------------------------------------------
Unit SysUtils
函数原型 function StrToTime(const S: string): TDateTime;
范例
procedure TForm1.Button1Click(Sender: TObject);
var
ATime: TDateTime;
begin
ATime := StrToTime(Edit1.Text);
if ATime < 0.50 then
ShowMessage('Good Morning')
else
ShowMessage('Good Afternoon');
end;
--------------------------------------------------------
Time 传回目前的时间.
--------------------------------------------------------
Unit SysUtils
函数原型 function Time: TDateTime;
范例
procedure TForm1.Timer1Timer(Sender: TObject);
var
DateTime : TDateTime;
str : string;
begin
DateTime := Time; // store the current date and time
str := TimeToStr(DateTime); // convert the time into a string
Caption := str; // display the time on the form's caption
{ Note This could have been done with the following line of code:
Caption := TimeToStr(Time); }
end;
# Time, TimeToStr Example
--------------------------------------------------------
TimeToStr 时间转换成内定型字串.(09:20:15 PM)
--------------------------------------------------------
Unit SysUtils
函数原型 function TimeToStr(Time: TDateTime): string;
GetMem procedure 配置记忆体程序
New 配置指位器P的记忆体空间，
大小为P所指型态的大小.
--------------------------------------------------------
Dispose 释放New所配置的记忆体.
--------------------------------------------------------
Unit System
函数原型 procedure New(var P: Pointer);
函数原型 procedure Dispose(var P: Pointer);
范例 type
PListEntry = ^TListEntry;
TListEntry = record
Next: PListEntry;
Text: string;
Count: Integer;
end;
var
List, P: PListEntry;
begin
...
New(P);
P^.Next := List;
P^.Text := 'Hello world';
P^.Count := 1;
List := P;
...
Dispose(P);
…
end;
范例
type
Str18 = string[18];
var
P: ^Str18;
begin
New(P);
P^ := 'Now you see it...';
Dispose(P); { Now you don't... }
end;
--------------------------------------------------------
GetMem 配置指位器P的记忆体空间，大小可自行设定.
--------------------------------------------------------
范例
var
F: file;
Size: Integer;
Buffer: PChar;
begin
AssignFile(F, 'test.txt');
Reset(F, 1);
try
Size := FileSize(F);
GetMem(Buffer, Size);
try
BlockRead(F, Buffer^, Size);
ProcessFile(Buffer, Size);
finally
FreeMem(Buffer);
end;
finally
CloseFile(F);
end;
end;

系统相关的常用时间函数几乎都在这了.你问的问题每个准.只能这么答了.

Answer 2

date 函数 返回当前的日期

datetimetofiledate 函数 将delphi的日期格式转换为dos的日期格式

datetimetostr 函数 将日期时间格式转换为字符串

datetimetostring 函数 将日期时间格式转换为字符串

datetostr 函数 将日期格式转换为字符串

dayofweek 函数 返回星期的数值

dec 函数 递减变量值

decodedate 函数 将日期格式分解为年月日

decodetime 函数 将时间格式分解为时、分、秒、毫秒

参考资料：http://zhidao.baidu.com/question/12193547.html

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Answer 3

直接用now就可以获取系统时间了

Answer 4

注意：一定要在uses加上dateutils

Answer 5

时间的函数很多啊,你想问的是哪个?