How to change a file's date/time ?

I want to change the date/time of a file and tried it with the following code.
At run-time the error "invalid variant type conversion" occurs.
It has to do with the conversion of the filename-string, but I have no idea
what to change. Can anyone help me ?

Thanks in advance,
Tulip

var handle : THandle;
    ft : TFileTime;
    dt : TDateTime;
    st : TSystemTime;
    filename : String;
begin
  filename := 'C:\temp\test.txt';
  dt := EncodeDate(1999, 1, 1);
  dt := dt + EncodeTime(17, 30, 0, 0);
  DateTimeToSystemTime(dt, st);
  SystemTimeToFileTime(st, ft);
  handle := CreateFile(PChar(filename), GENERIC_WRITE, FILE_SHARE_READ, nil, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, NULL);
  SetFileTime(handle, nil, nil, @ft);
  CloseHandle(handle);
end;
TulipAsked:
Who is Participating?
I wear a lot of hats...

"The solutions and answers provided on Experts Exchange have been extremely helpful to me over the last few years. I wear a lot of hats - Developer, Database Administrator, Help Desk, etc., so I know a lot of things but not a lot about one thing. Experts Exchange gives me answers from people who do know a lot about one thing, in a easy to use platform." -Todd S.

XANCommented:
well, it's code correct executes on my computer (WindowsNT) - 0 (zero), not NULL

var
  handle : THandle;
  ft : TFileTime;
  dt : TDateTime;
  st : TSystemTime;
  filename : String;
begin
  filename := 'C:\temp\test.txt';
  dt := EncodeDate(1999, 1, 1);
  dt := dt + EncodeTime(17, 30, 0, 0);
  DateTimeToSystemTime(dt, st);
  SystemTimeToFileTime(st, ft);
  handle := CreateFile(PChar(filename), GENERIC_WRITE, FILE_SHARE_READ, nil, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, 0);
  SetFileTime(handle, nil, nil, @ft);
  CloseHandle(handle);

Good luck :)
0

Experts Exchange Solution brought to you by

Your issues matter to us.

Facing a tech roadblock? Get the help and guidance you need from experienced professionals who care. Ask your question anytime, anywhere, with no hassle.

Start your 7-day free trial
It's more than this solution.Get answers and train to solve all your tech problems - anytime, anywhere.Try it for free Edge Out The Competitionfor your dream job with proven skills and certifications.Get started today Stand Outas the employee with proven skills.Start learning today for free Move Your Career Forwardwith certification training in the latest technologies.Start your trial today
Delphi

From novice to tech pro — start learning today.