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相关链接:[Delphi6函数大全1 2 3 4 5 ] [Delphi 7.0常用函数速查手册] [ Delphi 函数集及实例1 2 3 4 5 ]

综合应用
--------------------------------------------------------
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;
--------------------------------------------------------
ForceDirectories 目录
---------------------------------------------------------
Unit FileCtrl
函数原型 function ForceDirectories(Dir: string): Boolean;

procedure TForm1.Button1Click(Sender: TObject);
var
Dir: string;
begin
Dir := 'C:\APPS\SALES\LOCAL';
if DirectoryExists(Dir) then
Label1.Caption := Dir + ' was created'
end;
--------------------------------------------------------
ExpandUNCFileName 同上(只是得到网路上的路径)
--------------------------------------------------------
Unit SysUtils
函数原型 function ExpandUNCFileName(const FileName: string):string;
ExtractFileDir 分析字串中的路径
Unit SysUtils
函数原型 function ExtractFileDir(const FileName: string): string;
说明 设S字串为 c:\windows\abc.txt
则结果为 c:\windows
**** 功能在於由任何部份传来的叁数,加以分析它的路径
范例 procedure TForm1.Button1Click(Sender: TObject);
var
S: String;
P1:String;
begin
P1:='c:\windows\abc.txt';
S:=ExtractFileDir(P1);
Label1.Caption:=S;
end;

S=='c:\windows'

P1:='abc.txt'
S==''

P1:='c:abc.txt'
S=='c:'

P1:='c:\abc.txt'
S=='c:\'
--------------------------------------------------------
ExtractFileDrive 分析字串中的磁碟机名称
--------------------------------------------------------
Unit SysUtils
函数原型 function ExtractFileDrive(const FileName: string): string;
**** 功能同上,只是传回磁碟机名称.
范例 procedure TForm1.Button1Click(Sender: TObject);
var
S: String;
P1:String;
begin
P1:='c:\windows\abc.txt';
S:=ExtractFileDrive(P1);
Label1.Caption:=S;
end;

S:='c:'

P1:='abc.txt'
S==''
--------------------------------------------------------
ExtractFileExt 分析字串中的档案名称的副档名
--------------------------------------------------------
Unit SysUtils
函数原型 function ExtractFileExt(const FileName: string): string;
范例 procedure TForm1.Button1Click(Sender: TObject);
var
S: String;
P1:String;
begin
P1:='c:\windows\abc.txt';
S:=ExtractFileExt(P1);
Label1.Caption:=S;
end;

S=='.txt'

P1:='c:\windows\abc'
S==''
范例 MyFilesExtension := ExtractFileExt(MyFileName);
--------------------------------------------------------
ExtractFileName 分析字串中的档案名称(只传回档案名称)
--------------------------------------------------------
Unit SysUtils
函数原型 function ExtractFileName(const FileName: string): string;
范例 procedure TForm1.Button1Click(Sender: TObject);
var
S: String;
P1:String;
begin
P1:='c:\windows\abc.txt';
S:=ExtractFileName(P1);
Label1.Caption:=S;
end;

S=='abc.txt'
范例
procedure TForm1.Button1Click(Sender: TObject);
var
BackupName: string;
FileHandle: Integer;
StringLen: Integer;
X: Integer;
Y: Integer;
begin
if SaveDialog1.Execute then
begin
if FileExists(SaveDialog1.FileName) then
begin
BackupName := ExtractFileName(SaveDialog1.FileName);
BackupName := ChangeFileExt(BackupName, '.BAK');
if not RenameFile(SaveDialog1.FileName, BackupName) then
raise Exception.Create('Unable to create backup file.');
end;
FileHandle := FileCreate(SaveDialog1.FileName);
{ Write out the number of rows and columns in the grid. }
FileWrite(FileHandle,
StringGrid1.ColCount, SizeOf(StringGrid1.ColCount));
FileWrite(FileHandle,
StringGrid1.RowCount, SizeOf(StringGrid1.RowCount));
for X := 0 to StringGrid1.ColCount ? 1 do
begin
for Y := 0 to StringGrid1.RowCount ? 1 do
begin
{ Write out the length of each string, followed by the string itself. }
StringLen := Length(StringGrid1.Cells[X,Y]);
FileWrite(FileHandle, StringLen, SizeOf(StringLen));
FileWrite(FileHandle,
StringGrid1.Cells[X,Y], Length(StringGrid1.Cells[X,Y]);
end;
end;
FileClose(FileHandle);
end;
end;
##FileExists, RenameFile, FileCreate, FileWrite, FileClose, ExtractFileName Example
--------------------------------------------------------
ExtractFilePath 分析字串中的路径
--------------------------------------------------------
Unit SysUtils
函数原型 function ExtractFilePath(const FileName: string): string;
说明 设S字串为 c:\windows\abc.txt
则结果为 c:\windows\
范例 procedure TForm1.Button1Click(Sender: TObject);
var
S: String;
P1:String;
begin
P1:='c:\windows\abc.txt';
S:=ExtractFilePath(P1);
Label1.Caption:=S;
end;
范例
begin
with Session do
begin
ConfigMode := cmSession;
try
AddStandardAlias('TEMPDB', ExtractFilePath(ParamStr(0)), 'PARADOX');
finally
ConfigMode := cmAll;
end;
end;
##ConfigMode, AddStandardAlias, ExtractFilePath example
--------------------------------------------------------
FileSearch 寻找档案在磁碟机中的正确路径
--------------------------------------------------------
Unit SysUtils
函数原型 function FileSearch(const Name, DirList: string): string;
范例 var
s:string;
begin
s:= FileSearch('abc.txt', 'c:\window\');
Label1.Caption:=s;
end;
说明 找到传回c:\window\abc.txt 找不到传回空字串.
范例
procedure TForm1.Button1Click(Sender: TObject);
var
buffer: array [0..255] of char;
FileToFind: string;
begin
GetWindowsDirectory(buffer, SizeOf(buffer));
FileToFind := FileSearch(Edit1.Text, GetCurrentDir + ';' + buffer);
if FileToFind = '' then
ShowMessage('Couldn''t find ' + Edit1.Text + '.')
else
ShowMessage('Found ' + FileToFind + '.');
end;
##FileSearch, ShowMessage Example
--------------------------------------------------------
FileAge 传回档案的日期及时间(DOS型态).
--------------------------------------------------------
Unit SysUtils
函数原型 function FileAge(const FileName: string): Integer;
说明 就是档案总管中档案内容裹面的修改日期.
范例 procedure TForm1.Button1Click(Sender: TObject);
var
S: String;
FileDate1:Integer;
DateTime1:TDateTime;
begin
FileDate1 := FileAge('c:\delphi_d\delphi_help1.txt');
DateTime1 := FileDateToDateTime(FileDate1);
S := DateTimeToStr(DateTime1);
Label1.Caption:=S;
end;
--------------------------------------------------------
FileDateToDateTime 将DOS型态的日期时间转换为TDateTime型态.
--------------------------------------------------------
Unit SysUtils
函数原型 function FileDateToDateTime(FileDate: Integer):TDateTime;
-----------------------------------------------------------------------------
DateTimeToFileDate 将TDateTime型态的日期时间转换为 DOS型态.
-----------------------------------------------------------------------------
Unit SysUtils
函数原型 function DateTimeToFileDate(DateTime: TDateTime):Integer;
FileGetDate 传回档案的日期及时间(DOS型态).
Unit SysUtils
函数原型 function FileGetDate(Handle: Integer): Integer;
说明 就是档案总管中档案内容裹面的修改日期.
范例 procedure TForm1.Button1Click(Sender: TObject);
var
FileHandle:Integer;
S: String;
FileDate1:Integer;
DateTime1:TDateTime;
begin
FileHandle :=FileOpen('c:\delphi_d\delphi_help2.txt',
fmOpenReadWrite);
if FileHandle > 0 then
Begin
FileDate1 := FileGetDate(FileHandle);
DateTime1 := FileDateToDateTime(FileDate1);
S := DateTimeToStr(DateTime1);
FileClose(FileHandle);
End
else
S := 'Open File Error';
Label1.Caption:=S;
end;
-----------------------------------------------------------------------------
FileSetDate 设定档案的日期及时间(DOS型态).
-----------------------------------------------------------------------------
Unit SysUtils
函数原型 function FileSetDate(Handle: Integer; Age: Integer): Integer;
说明 传回值为0表示成功.
-----------------------------------------------------------------------------
DeleteFile 删除档案
-----------------------------------------------------------------------------
Unit SysUtils
函数原型 function DeleteFile(const FileName: string): Boolean;
范例 一 DeleteFile('DELETE.ME');

范例 二 if FileExists(FileName) then
if MessageDlg('Do you really want to delete ' +
ExtractFileName(FileName) + '?'), []) = IDYes then
DeleteFile(FileName);
##FileExists, DeleteFile Example
-----------------------------------------------------------------------------
RenameFile 更改档名
-----------------------------------------------------------------------------
Unit SysUtils
函数原型 function RenameFile(const OldName, NewName: string):Boolean;
范例
procedure TForm1.Button1Click(Sender: TObject);
var
BackupName: string;
FileHandle: Integer;
StringLen: Integer;
X: Integer;
Y: Integer;
begin
if SaveDialog1.Execute then
begin
if FileExists(SaveDialog1.FileName) then
begin
BackupName := ExtractFileName(SaveDialog1.FileName);
BackupName := ChangeFileExt(BackupName, '.BAK');
if not RenameFile(SaveDialog1.FileName, BackupName) then
raise Exception.Create('Unable to create backup file.');
end;
FileHandle := FileCreate(SaveDialog1.FileName);
{ Write out the number of rows and columns in the grid. }
FileWrite(FileHandle,
StringGrid1.ColCount, SizeOf(StringGrid1.ColCount));
FileWrite(FileHandle,
StringGrid1.RowCount, SizeOf(StringGrid1.RowCount));
for X := 0 to StringGrid1.ColCount ? 1 do
begin
for Y := 0 to StringGrid1.RowCount ? 1 do
begin
{ Write out the length of each string, followed by the string itself. }
StringLen := Length(StringGrid1.Cells[X,Y]);
FileWrite(FileHandle, StringLen, SizeOf(StringLen));
FileWrite(FileHandle,
StringGrid1.Cells[X,Y], Length(StringGrid1.Cells[X,Y]);
end;
end;
FileClose(FileHandle);
end;
end;
-----------------------------------------------------------------------------
DiskFree 磁碟机剩馀空间(Bytes)
-----------------------------------------------------------------------------
Unit SysUtils
函数原型 function DiskFree(Drive: Byte): Integer;
范例 var
S: string;
begin
S := IntToStr(DiskFree(0) div 1024) + ' Kbytes free.';
Label1.Caption:=S;
end;
说明 Drive
0=目前磁碟机,1=A磁碟机,2=B磁碟机...传回值若为-1,表示磁碟机侦测错误.
范例
var
S: string;
AmtFree: Int64;
Total: Int64;
begin
AmtFree := DiskFree(0);
Total := DiskSize(0);
S := IntToStr(AmtFree div Total) + 'percent of the space on drive 0 is free: ' (AmtFree div 1024) + ' Kbytes free. ';
Canvas.TextOut(10, 10, S);
end;
##DiskFree, DiskSize Example
-----------------------------------------------------------------------------
DiskSize 磁碟机空间大小(Bytes)
-----------------------------------------------------------------------------
Unit SysUtils
函数原型 function DiskSize(Drive: Byte): Integer;
范例 var
S: string;
begin
S := IntToStr(DiskSize(0) div 1024) + ' Kbytes free.';
Label1.Caption:=S;
end;
说明 Drive
0=目前磁碟机,1=A磁碟机,2=B磁碟机....传回值若为-1,表示磁碟机侦测错误.
##DiskFree, DiskSize Example
-----------------------------------------------------------------------------
FileExists 判断档案是否存在.
-----------------------------------------------------------------------------
Unit SysUtils
函数原型 function FileExists(const FileName: string): Boolean;
类似 FileExists, RenameFile, FileCreate, FileWrite, FileClose, ExtractFileName Example
范例
procedure TForm1.Button1Click(Sender: TObject);
var
BackupName: string;
FileHandle: Integer;
StringLen: Integer;
X: Integer;
Y: Integer;
begin
if SaveDialog1.Execute then
begin
if FileExists(SaveDialog1.FileName) then
begin
BackupName := ExtractFileName(SaveDialog1.FileName);
BackupName := ChangeFileExt(BackupName, '.BAK');
if not RenameFile(SaveDialog1.FileName, BackupName) then
raise Exception.Create('Unable to create backup file.');
end;
FileHandle := FileCreate(SaveDialog1.FileName);
{ Write out the number of rows and columns in the grid. }
FileWrite(FileHandle,
StringGrid1.ColCount, SizeOf(StringGrid1.ColCount));
FileWrite(FileHandle,
StringGrid1.RowCount, SizeOf(StringGrid1.RowCount));
for X := 0 to StringGrid1.ColCount ? 1 do
begin
for Y := 0 to StringGrid1.RowCount ? 1 do
begin
{ Write out the length of each string, followed by the string itself. }
StringLen := Length(StringGrid1.Cells[X,Y]);
FileWrite(FileHandle, StringLen, SizeOf(StringLen));
FileWrite(FileHandle,
StringGrid1.Cells[X,Y], Length(StringGrid1.Cells[X,Y]);
end;
end;
FileClose(FileHandle);
end;
end;
##FileExists, DeleteFile Example
##FileExists, RenameFile, FileCreate, FileWrite, FileClose, ExtractFileName Example
-----------------------------------------------------------------------------
FileOpen 开档.
-----------------------------------------------------------------------------
Unit SysUtils
函数原型 function FileOpen(const FileName: string; Mode:
Integer):Integer;
**** 开档失败传回-1.
说明 以下有关档案读取都属低阶,如Dos Int 21h中有关档案的部
分.
fmOpenRead = $0000;
fmOpenWrite = $0001;
fmOpenReadWrite = $0002;
fmShareCompat = $0000;
fmShareExclusive = $0010;
fmShareDenyWrite = $0020;
fmShareDenyRead = $0030;
fmShareDenyNone = $0040;

fmOpenRead Open for read access only.
FmOpenWrite Open for write access only.
FmOpenReadWrite Open for read and write access.
fmShareCompat Compatible with the way FCBs are
opened.
fmShareExclusive Read and write access is denied.
fmShareDenyWrite Write access is denied.
fmShareDenyRead Read access is denied.
fmShareDenyNone Allows full access for others.
范例
procedure OpenForShare(const FileName: String);
var
FileHandle : Integer;
begin
FileHandle := FileOpen(FileName, fmOpenWrite or fmShareDenyNone);
if FileHandle > 0 then
{valid file handle}
else
{Open error: FileHandle = negative DOS error code}
end;
范例
procedure TForm1.Button1Click(Sender: TObject);
var
iFileHandle: Integer;
iFileLength: Integer;
iBytesRead: Integer;
Buffer: PChar;
i: Integer
begin
if OpenDialog1.Execute then
begin
try
iFileHandle := FileOpen(OpenDialog1.FileName, fmOpenRead);
iFileLength := FileSeek(iFileHandle,0,2);
FileSeek(iFileHandle,0,0);
Buffer := PChar(AllocMem(iFileLength + 1));
iBytesRead = FileRead(iFileHandle, Buffer, iFileLength);
FileClose(iFileHandle);
for i := 0 to iBytesRead-1 do
begin
StringGrid1.RowCount := StringGrid1.RowCount + 1;
StringGrid1.Cells[1,i+1] := Buffer[i];
StringGrid1.Cells[2,i+1] := IntToStr(Integer(Buffer[i]));
end;
finally
FreeMem(Buffer);
end;
end;
end;
##FileOpen, FileSeek, FileRead Example
-----------------------------------------------------------------------------
FileCreate 建档
-----------------------------------------------------------------------------
Unit SysUtils
函数原型 function FileCreate(const FileName: string): Integer;

范例
procedure TForm1.Button1Click(Sender: TObject);
var
BackupName: string;
FileHandle: Integer;
StringLen: Integer;
X: Integer;
Y: Integer;
begin
if SaveDialog1.Execute then
begin
if FileExists(SaveDialog1.FileName) then
begin
BackupName := ExtractFileName(SaveDialog1.FileName);
BackupName := ChangeFileExt(BackupName, '.BAK');
if not RenameFile(SaveDialog1.FileName, BackupName) then

raise Exception.Create('Unable to create backup file.');
end;
FileHandle := FileCreate(SaveDialog1.FileName);
{ Write out the number of rows and columns in the grid. }
FileWrite(FileHandle,
StringGrid1.ColCount, SizeOf(StringGrid1.ColCount));
FileWrite(FileHandle,
StringGrid1.RowCount, SizeOf(StringGrid1.RowCount));
for X := 0 to StringGrid1.ColCount ? 1 do
begin

for Y := 0 to StringGrid1.RowCount ? 1 do
begin
{ Write out the length of each string, followed by the string itself. }
StringLen := Length(StringGrid1.Cells[X,Y]);
FileWrite(FileHandle, StringLen, SizeOf(StringLen));
FileWrite(FileHandle,
StringGrid1.Cells[X,Y], Length(StringGrid1.Cells[X,Y]);
end;
end;
FileClose(FileHandle);
end;

end;
##FileExists, RenameFile, FileCreate, FileWrite, FileClose, ExtractFileName Example
-----------------------------------------------------------------------------
FileClose 关档
-----------------------------------------------------------------------------
Unit SysUtils
函数原型 procedure FileClose(Handle: Integer);
范例
procedure TForm1.Button1Click(Sender: TObject);
var
BackupName: string;
FileHandle: Integer;
StringLen: Integer;
X: Integer;
Y: Integer;
begin
if SaveDialog1.Execute then
begin
if FileExists(SaveDialog1.FileName) then
begin
BackupName := ExtractFileName(SaveDialog1.FileName);
BackupName := ChangeFileExt(BackupName, '.BAK');
if not RenameFile(SaveDialog1.FileName, BackupName) then
raise Exception.Create('Unable to create backup file.');
end;
FileHandle := FileCreate(SaveDialog1.FileName);
{ Write out the number of rows and columns in the grid. }
FileWrite(FileHandle,
StringGrid1.ColCount, SizeOf(StringGrid1.ColCount));
FileWrite(FileHandle,
StringGrid1.RowCount, SizeOf(StringGrid1.RowCount));
for X := 0 to StringGrid1.ColCount ? 1 do
begin
for Y := 0 to StringGrid1.RowCount ? 1 do
begin
{ Write out the length of each string, followed by the string itself. }
StringLen := Length(StringGrid1.Cells[X,Y]);
FileWrite(FileHandle, StringLen, SizeOf(StringLen));
FileWrite(FileHandle,
StringGrid1.Cells[X,Y], Length(StringGrid1.Cells[X,Y]);
end;
end;
FileClose(FileHandle);
end;
end;
##FileExists, RenameFile, FileCreate, FileWrite, FileClose, ExtractFileName Example

============================================
**** 它是以Handle为叁数.
============================================
FileRead 读取档案
-----------------------------------------------------------------------------
Unit SysUtils
函数原型 function FileRead(Handle: Integer; var Buffer; Count: Integer):Integer;
范例
procedure TForm1.Button1Click(Sender: TObject);

var
iFileHandle: Integer;
iFileLength: Integer;
iBytesRead: Integer;
Buffer: PChar;
i: Integer
begin
if OpenDialog1.Execute then
begin
try
iFileHandle := FileOpen(OpenDialog1.FileName, fmOpenRead);
iFileLength := FileSeek(iFileHandle,0,2);
FileSeek(iFileHandle,0,0);
Buffer := PChar(AllocMem(iFileLength + 1));
iBytesRead = FileRead(iFileHandle, Buffer, iFileLength);
FileClose(iFileHandle);
for i := 0 to iBytesRead-1 do
begin
StringGrid1.RowCount := StringGrid1.RowCount + 1;
StringGrid1.Cells[1,i+1] := Buffer[i];
StringGrid1.Cells[2,i+1] := IntToStr(Integer(Buffer[i]));
end;
finally
FreeMem(Buffer);
end;
end;
end;
##FileOpen, FileSeek, FileRead Example
-----------------------------------------------------------------------------
FileWrite 写入档案
-----------------------------------------------------------------------------
Unit SysUtils
函数原型 function FileWrite(Handle: Integer; const Buffer; Count: Integer): Integer;
范例
procedure TForm1.Button1Click(Sender: TObject);
var
BackupName: string;
FileHandle: Integer;
StringLen: Integer;
X: Integer;
Y: Integer;
begin
if SaveDialog1.Execute then
begin
if FileExists(SaveDialog1.FileName) then
begin
BackupName := ExtractFileName(SaveDialog1.FileName);
BackupName := ChangeFileExt(BackupName, '.BAK');
if not RenameFile(SaveDialog1.FileName, BackupName) then
raise Exception.Create('Unable to create backup file.');
end;
FileHandle := FileCreate(SaveDialog1.FileName);
{ Write out the number of rows and columns in the grid. }
FileWrite(FileHandle,
StringGrid1.ColCount, SizeOf(StringGrid1.ColCount));
FileWrite(FileHandle,
StringGrid1.RowCount, SizeOf(StringGrid1.RowCount));
for X := 0 to StringGrid1.ColCount do
begin
for Y := 0 to StringGrid1.RowCount do
begin
{ Write out the length of each string, followed by the string itself. }
StringLen := Length(StringGrid1.Cells[X,Y]);
FileWrite(FileHandle, StringLen, SizeOf(StringLen));
FileWrite(FileHandle,
StringGrid1.Cells[X,Y], Length(StringGrid1.Cells[X,Y]);//?????????/
end;
end;
FileClose(FileHandle);
end;
end;
##FileExists, RenameFile, FileCreate, FileWrite, FileClose, ExtractFileName Example
-----------------------------------------------------------------------------
FileSeek 移动档案指标位置
-----------------------------------------------------------------------------
Unit SysUtils
函数原型 function FileSeek(Handle, Offset, Origin: Integer): Integer;
说明 Origin=0读/写指标由档案开头算起.
Origin=1读/写指标由目前位置算起.
Origin=2读/写指标移动到档案结束处.
**** 功能与Dos Int 21h 插断 42h 的功能相同.
失败传回-1.
范例 procedure TForm1.Button1Click(Sender: TObject);
var
FileHandle : Integer;
FileName : String;
Buffer : PChar;
S : String;
ReadBytes : Integer;
begin
FileName:='c:\delphi_test\abc.ttt';
S:='1234567890';
if FileExists(FileName) then
FileHandle := FileOpen(FileName, fmOpenReadWrite)
else
FileHandle := FileCreate(FileName);
if FileHandle < 0 then
Begin
MessageDlg('开档失败', mtInformation, [mbOk], 0);
Exit;
End;

GetMem(Buffer, 100);
try
StrPCopy(Buffer, S);
FileWrite(FileHandle,Buffer^,10);
FileSeek(FileHandle,4,0);
ReadBytes:=FileRead(FileHandle, Buffer^, 100);
Buffer[ReadBytes]:=#0;
Label1.Caption:=IntToStr(ReadBytes)+' '+
StrPas(Buffer);
finally
FreeMem(Buffer);
end;

FileClose(FileHandle);
end;

结果 存档後abc.ttt共有1234567890等十个Bytes.
从第五位元开始读取,共读取六个位元.
567890
(位移是从0开始算起)

procedure TForm1.Button1Click(Sender: TObject);

var
iFileHandle: Integer;
iFileLength: Integer;
iBytesRead: Integer;
Buffer: PChar;
i: Integer
begin
if OpenDialog1.Execute then
begin
try
iFileHandle := FileOpen(OpenDialog1.FileName, fmOpenRead);
iFileLength := FileSeek(iFileHandle,0,2);
FileSeek(iFileHandle,0,0);
Buffer := PChar(AllocMem(iFileLength + 1));
iBytesRead = FileRead(iFileHandle, Buffer, iFileLength);
FileClose(iFileHandle);
for i := 0 to iBytesRead-1 do
begin
StringGrid1.RowCount := StringGrid1.RowCount + 1;
StringGrid1.Cells[1,i+1] := Buffer[i];
StringGrid1.Cells[2,i+1] := IntToStr(Integer(Buffer[i]));
end;
finally
FreeMem(Buffer);
end;
end;
end;
##FileOpen, FileSeek, FileRead Example
-----------------------------------------------------------------------------
FileGetAttr 档案属性
-----------------------------------------------------------------------------
Unit SysUtils
函数原型 function FileGetAttr(const FileName: string): Integer;
说明 faReadOnly = $00000001;
faHidden = $00000002;
faSysFile = $00000004;
faVolumeID = $00000008;
faDirectory = $00000010;
faArchive = $00000020;
faAnyFile = $0000003F;
范例 procedure TForm1.Button1Click(Sender: TObject);
var
S: String;
begin
S:=IntToStr(FileGetAttr('c:\delphi_d\delphi_help1.txt'));
Label1.Caption := S;
end;
-----------------------------------------------------------------------------
FileSetAttr 设定档案属性
-----------------------------------------------------------------------------
Unit SysUtils
函数原型 function FileSetAttr(const FileName: string; Attr: Integer):
Integer;
说明 设定成功传回0
-----------------------------------------------------------------------------
FindClose 结束FindFirst/FindNext
-----------------------------------------------------------------------------
procedure TForm1.Button1Click(Sender: TObject);

var
sr: TSearchRec;
FileAttrs: Integer;
begin
StringGrid1.RowCount := 1;
if CheckBox1.Checked then
FileAttrs := faReadOnly
else
FileAttrs := 0;
if CheckBox2.Checked then
FileAttrs := FileAttrs + faHidden;
if CheckBox3.Checked then
FileAttrs := FileAttrs + faSysFile;
if CheckBox4.Checked then
FileAttrs := FileAttrs + faVolumeID;
if CheckBox5.Checked then

FileAttrs := FileAttrs + faDirectory;
if CheckBox6.Checked then
FileAttrs := FileAttrs + faArchive;
if CheckBox7.Checked then

FileAttrs := FileAttrs + faAnyFile;

if FindFirst(Edit1.Text, FileAttrs, sr) = 0 then

begin
with StringGrid1 do
begin
if (sr.Attr and FileAttrs) = sr.Attr then
begin
Cells[1,RowCount-1] := sr.Name;
Cells[2,RowCount-1] := IntToStr(sr.Size);
end;
while FindNext(sr) = 0 do
begin
if (sr.Attr and FileAttrs) = sr.Attr then
begin
RowCount := RowCount + 1;
Cells[1, RowCount-1] := sr.Name;

Cells[2, RowCount-1] := IntToStr(sr.Size);
end;
end;
FindClose(sr);
end;
end;
end;
##FindFirst, FindNext, FindClose Example
-----------------------------------------------------------------------------
FindFirst 寻找第一个符合的档案.
-----------------------------------------------------------------------------
procedure TForm1.Button1Click(Sender: TObject);

var
sr: TSearchRec;
FileAttrs: Integer;
begin
StringGrid1.RowCount := 1;
if CheckBox1.Checked then
FileAttrs := faReadOnly
else
FileAttrs := 0;
if CheckBox2.Checked then
FileAttrs := FileAttrs + faHidden;
if CheckBox3.Checked then
FileAttrs := FileAttrs + faSysFile;
if CheckBox4.Checked then
FileAttrs := FileAttrs + faVolumeID;
if CheckBox5.Checked then

FileAttrs := FileAttrs + faDirectory;
if CheckBox6.Checked then
FileAttrs := FileAttrs + faArchive;
if CheckBox7.Checked then

FileAttrs := FileAttrs + faAnyFile;

if FindFirst(Edit1.Text, FileAttrs, sr) = 0 then

begin
with StringGrid1 do
begin
if (sr.Attr and FileAttrs) = sr.Attr then
begin
Cells[1,RowCount-1] := sr.Name;
Cells[2,RowCount-1] := IntToStr(sr.Size);
end;
while FindNext(sr) = 0 do
begin
if (sr.Attr and FileAttrs) = sr.Attr then
begin
RowCount := RowCount + 1;
Cells[1, RowCount-1] := sr.Name;
Cells[2, RowCount-1] := IntToStr(sr.Size);
end;
end;
FindClose(sr);
end;
end;
end;
##FindFirst, FindNext, FindClose Example
-----------------------------------------------------------------------------
FindNext 寻找下一个符合的档案.
-----------------------------------------------------------------------------
Unit SysUtils
函数原型 procedure FindClose(var F: TSearchRec);
函数原型 function FindFirst(const Path: string; Attr: Integer;
var F: TSearchRec): Integer;
函数原型 function FindNext(var F: TSearchRec): Integer;
说明 成功传回0
范例 var
SRec: TSearchRec;
procedure TForm1.SearchClick(Sender: TObject);
begin
FindFirst('c:\delphi\bin\*.*', faAnyFile, SRec);
Label1.Caption := SRec.Name + ' is ' + IntToStr(SRec.Size) +
' bytes in size';
end;
procedure TForm1.AgainClick(Sender: TObject);
begin
FindNext(SRec);
Label1.Caption := SRec.Name + ' is ' + IntToStr(SRec.Size) +
' bytes in size';
end;
procedure TForm1.FormClose(Sender: TObject);
begin
FindClose(SRec);
end

TSearchRec = record
Time: Integer;
Size: Integer;
Attr: Integer;
Name: TFileName;
xcludeAttr: Integer;
FindHandle: THandle;
FindData: TWin32FindData;
end;

============================================
Floating-point conversion routines 浮点数转换函式
============================================
FloatToDecimal 将浮点数转换为十进位数.
-----------------------------------------------------------------------------
Unit SysUtils
函数原型 procedure FloatToDecimal(var Result: TFloatRec; const Value;
ValueType: TFloatValue; Precision, Decimals: Integer);
-----------------------------------------------------------------------------
FloatToStrF 将浮点数转换为格式化字串.
-----------------------------------------------------------------------------
Unit SysUtils
函数原型 function FloatToStrF(Value: Extended; Format: TFloatFormat;
Precision,Digits: Integer): string;
-----------------------------------------------------------------------------
FloatToStr 将浮点数转换为字串.
-----------------------------------------------------------------------------
Unit SysUtils
函数原型 function FloatToStr(Value: Extended): string;
-----------------------------------------------------------------------------
FloatToText 将浮点数转换为格式化十进位.
-----------------------------------------------------------------------------
Unit SysUtils
函数原型 function FloatToText(Buffer: PChar; const Value; ValueType:
TFloatValue;Format: TFloatFormat; Precision, Digits:
Integer): Integer;
-----------------------------------------------------------------------------
FloatToTextFmt 将浮点数转换为格式化十进位.
-----------------------------------------------------------------------------
Unit SysUtils
函数原型 function FloatToTextFmt(Buffer: PChar; const Value;
ValueType: TFloatValue; Format: PChar): Integer;
-----------------------------------------------------------------------------
FormatFloat 将浮点数转换为格式化字串.
-----------------------------------------------------------------------------
Unit SysUtils
函数原型 function FormatFloat(const Format: string; Value: Extended):
string;
-----------------------------------------------------------------------------
StrToFloat 将字串转换为浮点数.
-----------------------------------------------------------------------------
Unit SysUtils
函数原型 function StrToFloat(const S: string): Extended;
范例 procedure TForm1.Button1Click(Sender: TObject);
var
Value:Double;
S:String;
begin
S:=' 1234.56 ';
Value:=StrToFloat(S);
Label1.Caption:=Format('转换为 [%9.3f]',[Value]);
end;

注意 若S字串含有非数字字元,会产生错误讯号.
-----------------------------------------------------------------------------
TextToFloat 将 null-terminated 字串转换为浮点数.
-----------------------------------------------------------------------------
Unit SysUtils
函数原型 function TextToFloat(Buffer: PChar; var Value; ValueType:
TFloatValue): Boolean;

===========================================
Flow-control routines 流程控制常式
===========================================
Break 从 for, while, or repeat 终止跳出.
-----------------------------------------------------------------------------
Unit System
函数原型 procedure Break;
范例 var
S: string;
begin
while True do
begin
ReadLn(S);
try
if S = '' then Break;
WriteLn(S);
finally
{ do something for all cases }
end;
end;
end;
-----------------------------------------------------------------------------
Continue 从 for, while, or repeat 继续执行.
-----------------------------------------------------------------------------
Unit System
函数原型 procedure Continue;
范例 var
F: File;
i: integer;
begin
for i := 0 to (FileListBox1.Items.Count - 1) do
begin
try
if FileListBox1.Selected[i] then
begin
if not FileExists(FileListBox1.Items.Strings[i]) then
begin
MessageDlg('File: ' +FileListBox1.Items.Strings[i]
+ ' not found', mtError, [mbOk], 0);
Continue;
end;
AssignFile(F, FileListBox1.Items.Strings[i]);
Reset(F, 1);
ListBox1.Items.Add(IntToStr(FileSize(F)));
CloseFile(F);
end;
finally
{ do something here }
end;
end;
end;
范例
var
F: File;
i: Integer;
begin
for i := 0 to (FileListBox1.Items.Count - 1) do begin
try
if FileListBox1.Selected[i] then
begin
if not FileExists(FileListBox1.Items.Strings[i]) then begin
MessageDlg('File: ' + FileListBox1.Items.Strings[i] +
' not found', mtError, [mbOk], 0);
Continue;
end;
AssignFile(F, FileListBox1.Items.Strings[i]);

Reset(F, 1);
ListBox1.Items.Add(IntToStr(FileSize(F)));
CloseFile(F);
end;
finally
{ do something here }
end;
end;
end;
## Continue, Items, Selected Example
-----------------------------------------------------------------------------
Exit 直接离开一个程序.
-----------------------------------------------------------------------------
Unit System
函数原型 procedure Exit;
-----------------------------------------------------------------------------
Halt 结束程式返回作业系统.
-----------------------------------------------------------------------------
Unit System
函数原型 procedure Halt [ ( Exitcode: Integer) ];
范例 begin
if 1 = 1 then
begin
if 2 = 2 then
begin
if 3 = 3 then
begin
Halt(1); { Halt right here! }
end;
end;
end;
Canvas.TextOut(10, 10, 'This will not be executed');
end;
-----------------------------------------------------------------------------
RunError 停止程式执行且执行run-time error.
-----------------------------------------------------------------------------
Unit System
函数原型 procedure RunError [ ( Errorcode: Byte ) ];
范例 begin
{$IFDEF Debug}
if P = nil then
RunError(204);
{$ENDIF}
end;

=====================================
I/O routines I/O常式
=====================================
AssignFile 指定档案给一个档案变数.
-----------------------------------------------------------------------------
Unit System
函数原型 procedure AssignFile(var F; FileName: string);
说明 **一个档案不可重复执行AssignFile两次以上.
Example
var
F: TextFile;
S: string;
begin
if OpenDialog1.Execute then { Display Open dialog box }
begin
AssignFile(F, OpenDialog1.FileName); { File selected in dialog box }
Reset(F);
Readln(F, S); { Read the first line out of the file }
Edit1.Text := S; { Put string in a TEdit control }
CloseFile(F);
end;
end;
## AssignFile, OpenDialog, Readln, CloseFile Example
-----------------------------------------------------------------------------
CloseFile 关闭档案.
-----------------------------------------------------------------------------
Unit System
函数原型 procedure CloseFile(var F);
#### AssignFile, OpenDialog, Readln, CloseFile Example
-----------------------------------------------------------------------------
IOResult 传回最近一次执行I/O函数,是否有错误.
-----------------------------------------------------------------------------
Unit System
函数原型 function IOResult: Integer;
范例 var
F: file of Byte;
S: String;
begin
S:= 'c:\ka\aaa.txt';
AssignFile(F, S);
{$I-}
Reset(F);
{$I+}
if IOResult = 0 then
Label1.Caption:='File size in bytes: ' +
IntToStr(FileSize(F);
else
Label1.Caption:='开档失败';
end;
说明 传回0表示没有错误.
EXAMPLE
var
F: file of Byte;
begin
if OpenDialog1.Execute then begin
AssignFile(F, OpenDialog1.FileName);
{$I-}
Reset(F);
{$I+}
if IOResult = 0 then
MessageDlg('File size in bytes: ' + IntToStr(FileSize(F)),
mtInformation, [mbOk], 0)
else
MessageDlg('File access error', mtWarning, [mbOk], 0);
end;
end;
-----------------------------------------------------------------------------
Reset 开起一个可供读取的档案.
-----------------------------------------------------------------------------
Unit System
函数原型 procedure Reset(var F [: File; RecSize: Word ] );
-----------------------------------------------------------------------------
Rewrite 建立一个可供写入的新档案.
-----------------------------------------------------------------------------
Unit System
函数原型 procedure Rewrite(var F: File [; Recsize: Word ] );
范例 procedure TForm1.Button1Click(Sender: TObject);
var
F: TextFile;
I1,I2,I3:Integer;
S1,S2,S3:String;
begin
I1:=1234;
I2:=5678;
I3:=90;
S1:='abcd';
S2:='efgh';
S3:='ij';
AssignFile(F,'c:\ka\aaa.txt');
Rewrite(F);
Write(F,I1);
Write(F,I2);
Write(F,I3);
Write(F,S1);
Write(F,S2);
Write(F,S3);
Write(F,I1,I2,I3);
Write(F,S1,S2,S3);
Writeln(F,I1);
Writeln(F,I2);
Writeln(F,I3);
Writeln(F,S1);
Writeln(F,S2);
Writeln(F,S3);
Writeln(F,I1,I2,I3);
Writeln(F,S1,S2,S3);

Reset(F);
Readln(F, S1);
Readln(F, I1);
Label1.Caption:=S1+' '+IntToStr(I1);
CloseFile(F);
end;

结果 1234567890abcdefghij1234567890abcdefghij1234..
5678..
90..
abcd..
efgh..
ij..
1234567890..
abcdefghij..
abcdefghij..

以上是存档结果,两点代表#13#10,两个位元.
以Writeln存档者,多出换行符号#13#10.
且如果以Writeln(F,I1,I2,I3)会当成同一串列,
变数间没有间隔符号,造成Read时得不到预期的效果.

读取结果
S1=1234567890abcdefghij1234567890abcdefghij1234
长度44且不含#13#10两个位元.
I1=5678

** Write(F,I1:10:2,I2:8:2);
具有格式化的功能,如同Str.

范例 procedure TForm1.Button1Click(Sender: TObject);
var
F: file of Byte;
I1,I2,I3:Byte;
begin
I1:=16;
I2:=32;
I3:=48;
AssignFile(F,'c:\ka\aaa.txt');
Rewrite(F);
Write(F,I1);
Write(F,I2);
Write(F,I3);
Write(F,I1,I2,I3);

I1:=0;
Reset(F);
Read(F, I1);

Label1.Caption:=IntToStr(I1);
CloseFile(F);
end;

结果 file of Byte 及 file of record
只能以Write及Read,来写入及读取,
不可以Writeln及Readln.

范例 procedure TForm1.Button1Click(Sender: TObject);
type
ppRec = record
pp_No:String[5];
pp_Name:String[10];
pp_Age:Integer;
pp_Sum:Double;
end;
var
Rec : ppRec;
Rec2: ppRec;
F: file of ppRec;
begin
With Rec do
Begin
pp_No:='0001';
pp_Name:='abc';
pp_Age:=12;
pp_Sum:=600;
End;

AssignFile(F,'c:\ka\aaa.txt');
Rewrite(F);
Write(F,Rec);

Rec.pp_No:='0002';
Rec.pp_Sum:=58.2;
Write(F,Rec);

Rec.pp_No:='0003';
Rec.pp_Sum:=258.242;
Write(F,Rec);

seek(F,1);
Read(F,Rec2);

seek(F,1);
Truncate(F); {删除,只剩第0笔}

Canvas.TextOut(5,10,Rec2.pp_No);
Canvas.TextOut(5,30,Rec2.pp_Name);
Canvas.TextOut(5,50,Format('%d',[Rec2.pp_Age]));
Canvas.TextOut(5,70,Format('%f',[Rec2.pp_Sum]));

CloseFile(F);
end;

结果 pp_No存入6 Bytes
pp_Name存入11 Bytes
pp_Age存入4 Bytes(Integer 4 Bytes)
pp_Sum存入8 Bytes(Double 8 Bytes)

整个Record以16的倍数存档.
EXAMPLE
var F: TextFile;
begin
AssignFile(F, 'NEWFILE.$$$');
Rewrite(F);
Writeln(F, 'Just created file with this text in it...');
CloseFile(F);
end;
-----------------------------------------------------------------------------
Seek 移动档案指标.
-----------------------------------------------------------------------------
Unit System
函数原型 procedure Seek(var F; N: Longint);
说明 Seek从0开始.
Example
var
f: file of Byte;
size : Longint;
S: string;
y: Integer;
begin
if OpenDialog1.Execute then
begin
AssignFile(f, OpenDialog1.FileName);
Reset(f);
size := FileSize(f);
S := 'File size in bytes: ' + IntToStr(size);
y := 10;
Canvas.TextOut(5, y, S);
y := y + Canvas.TextHeight(S) + 5;
S := 'Seeking halfway into file...';
Canvas.TextOut(5, y, S);
y := y + Canvas.TextHeight(S) + 5;
Seek(f,size div 2);
S := 'Position is now ' + IntToStr(FilePos(f));
Canvas.TextOut(5, y, S);
CloseFile(f);
end;
end;
## FileSize, Seek, FilePos Example
-----------------------------------------------------------------------------
Truncate 将目前档案指标位置之後的档案内容全部删除.
-----------------------------------------------------------------------------
Unit System
函数原型 procedure Truncate(var F);
范例
var

f: file of Integer;
i,j: Integer;
begin
AssignFile(f,'TEST.INT');
Rewrite(f);
for i := 1 to 6 do
Write(f,i);
Writeln('File before truncation:');
Reset(f);
while not Eof(f) do
begin
Read(f,i);
Writeln(i);
end;
Reset(f);
for i := 1 to 3 do
Read(f,j); { Read ahead 3 records }
Truncate(f); { Cut file off here }

Writeln;
Writeln('File after truncation:');
Reset(f);
while not Eof(f) do
begin
Read(f,i);
Writeln(i);
end;
CloseFile(f);
Erase(f);
end;
-----------------------------------------------------------------------------
FilePos 传回目前档案的位置.
-----------------------------------------------------------------------------
Unit System
函数原型 function FilePos(var F): Longint
说明 F 不可为 Text File
档头 :FilePos(F):=0;
档尾 :Eof(F):=True;
范例 var
f: file of Byte;
S: string;
begin
S:= 'c:\ka\abc.txt';
AssignFile(f, S);
Reset(f);
Seek(f,1);
Label1.Caption := '现在位置 : ' + IntToStr(FilePos(f));
end;
Example
var
f: file of Byte;
size : Longint;
S: string;
y: Integer;
begin
if OpenDialog1.Execute then
begin
AssignFile(f, OpenDialog1.FileName);
Reset(f);
size := FileSize(f);
S := 'File size in bytes: ' + IntToStr(size);
y := 10;
Canvas.TextOut(5, y, S);
y := y + Canvas.TextHeight(S) + 5;
S := 'Seeking halfway into file...';
Canvas.TextOut(5, y, S);

y := y + Canvas.TextHeight(S) + 5;
Seek(f,size div 2);
S := 'Position is now ' + IntToStr(FilePos(f));
Canvas.TextOut(5, y, S);
CloseFile(f);
end;
end;
##FileSize, Seek, FilePos Example
-----------------------------------------------------------------------------
FileSize 档案长度.
-----------------------------------------------------------------------------
Unit System
函数原型 function FileSize(var F): Integer;
说明 F 不可为 Text File
如果F为record file,则传回record数,
否则传回Byte数.
## FileSize, Seek, FilePos Example
-----------------------------------------------------------------------------
Eof 测试档案是否结束.
-----------------------------------------------------------------------------
Unit System
函数原型 function Eof(var F): Boolean;
函数原型 function Eof [ (var F: Text) ]: Boolean;
范例 var
F1, F2: TextFile;
Ch: Char;
begin
if OpenDialog1.Execute then
begin
AssignFile(F1, OpenDialog1.Filename);
Reset(F1);
if SaveDialog1.Execute then
begin
AssignFile(F2, OpenDialog1.Filename);
Rewrite(F2);
while not Eof(F1) do
begin
Read(F1, Ch);
Write(F2, Ch);
end;
CloseFile(F2);
end;
CloseFile(F1);
end;
end;
Example
var

F1, F2: TextFile;
Ch: Char;
begin
if OpenDialog1.Execute then begin
AssignFile(F1, OpenDialog1.Filename);
Reset(F1);
if SaveDialog1.Execute then begin
AssignFile(F2, SaveDialog1.Filename);
Rewrite(F2);
while not Eof(F1) do
begin
Read(F1, Ch);
Write(F2, Ch);
end;
CloseFile(F2);
end;
CloseFile(F1);
end;
end;
-----------------------------------------------------------------------------
OpenPictureDialog OpenDialog 开启档案.
-----------------------------------------------------------------------------
//SavePictureDialog1.DefaultExt := GraphicExtension(TBitmap);
//SavePictureDialog1.Filter := GraphicFilter(TBitmap);

procedure TForm1.Button1Click(Sender: TObject);
var
Done: Boolean;
begin
OpenPictureDialog1.DefaultExt := GraphicExtension(TIcon);
OpenPictureDialog1.FileName := GraphicFileMask(TIcon);
OpenPictureDialog1.Filter := GraphicFilter(TIcon);
OpenPictureDialog1.Options := [ofFileMustExist, ofHideReadOnly, ofNoChangeDir ];
while not Done do
begin
if OpenPictureDialog1.Execute then
begin
if not (ofExtensionDifferent in OpenPictureDialog1.Options) then

begin
Application.Icon.LoadFromFile(OpenPictureDialog1.FileName);
Done := True;
end
else
OpenPictureDialog1.Options := OpenPictureDialog1.Options - ofExtensionDifferent;
end
else { User cancelled }
Done := True;
end;
end;

## Eof, Read, Write Example
-----------------------------------------------------------------------------
Erase 删除档案.
-----------------------------------------------------------------------------
Unit System
函数原型 procedure Erase(var F);
说明 要先关档後才可以执行.
范例 procedure TForm1.Button1Click(Sender: TObject);
var
F: Textfile;
begin
OpenDialog1.Title := 'Delete File';
if OpenDialog1.Execute then
begin
AssignFile(F, OpenDialog1.FileName);
try
Reset(F);
if MessageDlg('Erase ' + OpenDialog1.FileName +
'?',mtConfirmation, [mbYes, mbNo], 0) = mrYes then
begin
CloseFile(F);
Erase(F);
end;
except
on EInOutError do
MessageDlg('File I/O error.', mtError, [mbOk], 0);
end;
end;
end;
Example
procedure TForm1.Button1Click(Sender: TObject);

var
F: Textfile;
begin
OpenDialog1.Title := 'Delete File';
if OpenDialog1.Execute then begin
AssignFile(F, OpenDialog1.FileName);
try
Reset(F);
if MessageDlg('Erase ' + OpenDialog1.FileName + '?',
mtConfirmation, [mbYes, mbNo], 0) = mrYes then
begin
CloseFile(F);
Erase(F);
end;
except
on EInOutError do

MessageDlg('File I/O error.', mtError, [mbOk], 0);
end;
end;
end;
##Erase, OpenDialog.Title, OpenDialog.FileName Example
-----------------------------------------------------------------------------
Rename 更改档名.
-----------------------------------------------------------------------------
Unit System
函数原型 procedure Rename(var F; Newname);
范例 uses Dialogs;
var
f : file;
begin
OpenDialog1.Title := 'Choose a file... ';
if OpenDialog1.Execute then
begin
SaveDialog1.Title := 'Rename to...';
if SaveDialog1.Execute then
begin
AssignFile(f, OpenDialog1.FileName);
Canvas.TextOut(5, 10, 'Renaming ' +
OpenDialog1.FileName +' to ' +
SaveDialog1.FileName);
Rename(f, SaveDialog1.FileName);
end;
end;
end;
Example
uses Dialogs;
var

f : file;
begin
OpenDialog1.Title := 'Choose a file... ';
if OpenDialog1.Execute then begin
SaveDialog1.Title := 'Rename to...';
if SaveDialog1.Execute then begin
AssignFile(f, OpenDialog1.FileName);
Canvas.TextOut(5, 10, 'Renaming ' + OpenDialog1.FileName + ' to ' +
SaveDialog1.FileName);
Rename(f, SaveDialog1.FileName);
end;
end;
end;