Using Delphi to track changes made to folder?

Question

Hi there,

I need to writing a delphi program which will monitor a folder for changes (Add, update, rename and removal of files). Is the TShellChangeNotifier is way to go? To be honest, I have no idea how to use it.

Please help.

Thanks.

Answer 1

I think this article will help you: Monitoring System Shell Changes using Delphi

Basically it analyzes the TShellChangeNotifier, discards it and then goes for a TSHChangeNotify which is basically a wrapper for the SHChangeNotify windows api function.

Answer 2

This question might help. mghie's answer shows how to properly use ReadDirectoryChangesW.

Answer 3

i suggest using madShell

RegisterShellEvent(ShellEvent, pathToMonitor, false, [seItemCreated, seItemRenamed]);

//

procedure Tform.ShellEvent(event: TShellEventType; const obj1, obj2: IShellObj; drive: char; value: cardinal);
var
  filename: string;
  isReady: boolean;
begin
  if (event = seItemCreated) then
    filename := obj1.Path
  else if (event = seItemRenamed) then
    filename := obj2.Path
  else
    exit;

  // try to open to ensure it's read for reading
  repeat
    try
      TfileStream.Create(filename, fmOpenRead + fmShareExclusive).Free;
      isReady := true;
    except
      isReady := false;
      sleep(250);
    end;
  until (isReady) or (not FileExists(filename));

  OutputDebugString(pChar('ShellEvent: ' + filename));

end;