Delphi - Registryschlüssel überwachen

{
  Author  : http://www.michael-puff.de
  Date    : 2006-03-03
  License : PUBLIC DOMAIN
}

type
  TThreadParams = packed record
    Root: HKEY;
    Key:  String[255];
  end;
  PThreadParams = ^TThreadParams;

function WatchRegKey(Root: HKEY; Key: String): DWORD;
var
  err: DWORD;
  hEvent: THandle;
  hndlkey: HKEY;
begin
  hEvent := CreateEvent(nil, False, False, nil); 
  if hEvent <> 0 then
  begin 
    err := RegConnectRegistry(nil, Root, hndlkey);
    if err = 0 then 
    begin
      err := RegOpenKeyEx(hndlkey, PChar(Key), 0, KEY_NOTIFY, hndlkey); 
      if err = 0 then
      begin 
        err := RegNotifyChangeKeyValue(hndlkey, False, REG_NOTIFY_CHANGE_LAST_SET, hEvent, True);
        case WaitForSingleObject(hEvent, INFINITE) of 
          WAIT_OBJECT_0: ShowMessage('Kuckuck');
        end;
      end;
    end;
  end
  else
    err := GetLastError;
  result := err;
end;

function Thread(p: PThreadParams): Integer;
var
  Root: HKEY;
  Key: String;
  err: DWORD;
begin
  Root := p.Root;
  Key := p.Key;

  err := WatchRegKey(Root, Key);
  if err <> 0 then
    MessageBox(0, PChar(SysErrorMessage(err)), 'Error WatchRegkey', MB_ICONSTOP);

  Dispose(p);

  result := 0;
end;

procedure TForm1.Button1Click(Sender: TObject);
var
  ThreadID: Cardinal;
  ThreadParams: PThreadParams;
begin
  New(ThreadParams);
  ThreadParams.Root := HKEY_CURRENT_USER;
  ThreadParams.Key := 'Software\mp\Test';
  CloseHandle(BeginThread(nil, 0, @Thread, ThreadParams, 0, ThreadID));
end;

2012-01-26T23:14:49 +0100, mail[at]michael[Bindestrich]puff.de