bsp;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;
--------------------------------------------------------
FreeMem 释放GetMem所配置的记忆体.
--------------------------------------------------------
Unit System
函数原型 procedure GetMem(var P: Pointer; Size: Integer);
函数原型 procedure FreeMem(var P: Pointer[; Size: Integer]);
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;
====================================
File-management routines 档案管理常式
====================================
--------------------------------------------------------
ChangeFileExt 变更档案的副档名
--------------------------------------------------------
Unit SysUtils
函数原型 function ChangeFileExt(const FileName, Extension: string):
string;
范例 procedure TForm1.Button1Click(Sender: TObject);
var
S: String;
P1:String;
P2:String;
begin
P1:=''''abc.txt'''';
P2:=''''.ini'''';
S := ChangeFileExt(P1,P2);
Label1.Caption:=S;
end;
结果 S== ''''abc.ini''''
P1:=''''abc''''
P2:=''''.ini''''
S== ''''abc.ini''''
P1:=''''c:\windows\abc.txt''''
P2:=''''.ini''''
S==''''c:\windows\abc.ini''''
P1:=''''abc.txt''''
P2:=''''ini''''
S==''''abcini''''
**注意:P2的第一位元必须有一点''''.ini''''
范例
procedure TForm1.ConvertIcon2BitmapClick(Sender: TObject);
var
s : string;
Icon: TIcon;
begin
OpenDialog1.DefaultExt := ''''.ICO'''';
OpenDialog1.Filter := ''''icons (*.ico)|*.ICO'''';
OpenDialog1.Options := [ofOverwritePrompt, ofFileMustExist, ofHideReadOnly ];
if OpenDialog1.Execute then
begin
Icon := TIcon.Create;
try
Icon.Loadfromfile(OpenDialog1.FileName);
s:= ChangeFileExt(OpenDialog1.FileName,''''.BMP'''');
Image1.Width := Icon.Width;
Image1.Height := Icon.Height;
Image1.Canvas.Draw(0,0,Icon);
Image1.Picture.SaveToFile(s);
ShowMessage(OpenDialog1.FileName + '''' Saved to '''' + s);
finally
Icon.Free;
end;
end;
end;
# SaveToFile, Create, Height, Width, Canvas, ChangeFileExt example
--------------------------------------------------------
ExpandFileName 将档案名称加在目前所在之路径全名之後
--------------------------------------------------------
Unit SysUtils
函数原型 function ExpandFileName(const FileName: string): string;
说明 设目前目录为 c:\windows 档案名称为 abc.txt
则结果为 c:\windows\abc.txt
**** 此函数并不是求abc.txt的所在路径.
范例 procedure TForm1.Button1Click(Sender: TObject);
var
S: String;
begin
S:=ExpandFileName(''''abc.txt'''');
Label1.Caption:=S;
end;
范例
procedure TForm1.Button1Click(Sender: TObject)
begin
ListBox1.Items.Add(ExpandFileName(Edit1.Text));
end;
------------------------------------------------------------------
DirectoryExists 目录是否存在------------------------------------------------------------------
Unit
FileCtrl
uses FileCtrl;
procedure TForm1.Button1Click(Sender: TObject);
begin
if not DirectoryExists(''''c:\temp'''') then
if not CreateDir(''''C:\temp'''') then
raise Exception.Create(''''Cannot create c:\temp'''');
end;
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