p; 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
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