const
  FILE_CREATE_TIME = 0;  //创建时间
  FILE_MODIFY_TIME = 1;  //修改时间
  FILE_ACCESS_TIME = 3;  //访问时间

function TForm1.GetFileLastAccessTime(a_FileName: string;
  a_Flag: Byte): TDateTime;
var
  ffd: TWin32FindData;
  dft: DWord;
  lft: TFileTime;
  h: THandle;
begin
  h:=FindFirstFile(PChar(a_FileName),ffd);
  if h<>INVALID_HANDLE_VALUE then
  begin
    case a_Flag of
      FILE_CREATE_TIME:FileTimeToLocalFileTime(ffd.ftCreationTime,lft);
      FILE_MODIFY_TIME:FileTimeToLocalFileTime(ffd.ftLastWriteTime,lft);
      FILE_ACCESS_TIME:FileTimeToLocalFileTime(ffd.ftLastAccessTime,lft);
    else
      FileTimeToLocalFileTime(ffd.ftLastAccessTime,lft);
    end;
    FileTimeToDosDateTime(lft,LongRec(dft).Hi,LongRec(dft).Lo);
    Result := FileDateToDateTime(dft);
    Windows.FindClose(h);
  end
  else
  Result:=0;
end;