[SOLVED] Delphi Determine filesize in real time

Delphi Determine filesize in real time

Is it possible in Delphi to determine the size of a file as it is being copied? I get a notification when a file is first copied to a folder, but need to wait until the copy is complete before I can process the file.

I've used JclFileUtils.GetSizeOfFile(Filename) but that gives me the 'expected' file size, not the current filesize.

Solution

Prompted by the first answer I decided to give up on trying to determine when a file copy has completed. Instead I found that using TFileStream gave me a reliable indication whether a file is in use or not.

function IsFileInUse(Filename: string; var ResultMessage: string): boolean;
var
  Stream: TFileStream;
begin
  Result := True;
  ResultMessage := '';
  try
    Stream := TFileStream.Create(Filename, fmOpenRead or fmShareDenyWrite);
    try
      Result := False;
    finally
      FreeAndNil(Stream);
    end;

  Except on E: Exception do
    ResultMessage := 'IsFileInUse: ' + E.Message
  end;
end;

In this way I can keep on checking until the file is not in use anymore before attempting to process it.