Mega Code Archive
How to set a files compression state
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Title: How to set a files compression state
const
COMPRESSION_FORMAT_NONE = 0
COMPRESSION_FORMAT_LZNT1 = 2
COMPRESSION_FORMAT_DEFAULT = 1;
FILE_DEVICE_FILE_SYSTEM = 9;
METHOD_BUFFERED = 0;
FILE_READ_DATA = 1;
FILE_WRITE_DATA = 2;
FSCTL_SET_COMPRESSION = (FILE_DEVICE_FILE_SYSTEM shl 16) or
((FILE_READ_DATA or FILE_WRITE_DATA) shl 14) or (16 shl 2) or METHOD_BUFFERED;
function SetCompressedAttribut(FileName: PChar; forceCompress: Boolean): Boolean;
var
hnd: Integer;
Comp: SHORT;
res: DWORD;
begin
if forceCompress or ((GetFileAttributes(PChar(ExtractFilePath(FileName))) and
FILE_ATTRIBUTE_COMPRESSED) 0) then
begin
Result := False;
if (GetFileAttributes(FileName) and FILE_ATTRIBUTE_COMPRESSED) = 0 then
begin
hnd := CreateFile(FileName, GENERIC_READ + GENERIC_WRITE, 0, nil, OPEN_EXISTING, 0, 0);
try
Comp := COMPRESSION_FORMAT_DEFAULT;
if not DeviceIoControl(hnd, FSCTL_SET_COMPRESSION, @Comp,
SizeOf(SHORT), nil, 0, res, nil) then Exit;
finally
CloseHandle(hnd);
end;
end;
Result := True;
end
else
Result := True;
end;
procedure TForm1.Button1Click(Sender: TObject);
begin
if OpenDialog1.Execute then
begin
SetCompressedAttribut(PChar(OpenDialog1.FileName), True);
end;
end;
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