Delphi Help > Index > file management routines

Delphi Help > Index > file management routines
там екзамплы на абсолютно все функции...

VCL Reference
FileExists, RenameFile, FileCreate, FileWrite, FileClose, ExtractFileName Example

The following example uses a button, a string grid, and a Save dialog box on a form. When the button is clicked, the user is prompted for a filename. When the user clicks OK, the contents of the string grid are written to the specified file. Additional information is also written to the file so that it can be read easily with the FileRead function.

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;
---------------------------------------------------
VCL Reference
FileSeek function

See also Example

Repositions read/write point.

Unit

SysUtils

Category

file management routines

function FileSeek(Handle, Offset, Origin: Integer): Integer; overload;
function FileSeek(Handle: Integer; const Offset: Int64; Origin: Integer): Int64; overload;

Description

Use FileSeek to reposition the read/write point in a file that was opened with FileOpen or FileCreate. Handle is the file handle that was returned by FileOpen or FileCreate.

Offset specifies the number of bytes from Origin where the file pointer should be positioned. Origin is a code with three possible values, denoting the beginning of the file, the end of the file, and the current position of the file pointer.

Origin Action

0 The file pointer is positioned Offset bytes from the beginning of the file.
1 The file pointer is positioned Offset bytes from its current position.
2 The file pointer is positioned Offset bytes from the end of the file.

If FileSeek is successful, it returns the new position of the file pointer; otherwise, it returns -1.

Note: Do not mix routines that take or return file handles with those that use Pascal file variables (typically seen as var F). To move the file pointer in a file specified by a Pascal file variable, use the Seek procedure instead.






VCL Reference
FileOpen, FileSeek, FileRead Example


The following example uses a button, a string grid, and an Open dialog box on a form. When the button is clicked, the user is prompted for a filename. When the user clicks OK, the specified file is opened, read into a buffer, and closed. Then the buffer is displayed in two columns of the string grid. The first column contains the character values in the buffer. The second column contains the numeric values of the characters in the buffer.

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 ;
StringGrid1.Cells[2,i+1] := IntToStr(Integer(Buffer));
end;
finally
FreeMem(Buffer);
end;
end;
end;

Можно юзать связку еще с досовского паскаля Write фор типизед файлес и Seek и Read и все такое - короче екзамплы гляди по ним.... а то адми мне башку за спуффинг оторвет ...