如何查看目录的子文件是否已更改

Question

在Windows中,是否有一种简单的方法来判断文件夹是否有更改的子文件？

我验证了,当子文件更改时,文件夹上的最后修改日期不会更新.

我可以设置一个可以修改此行为的注册表项吗？

如果重要,我正在使用NTFS卷.

我最终希望从C++程序中获得这种能力.

递归扫描整个目录对我来说不起作用,因为文件夹太大了.

更新:我确实需要一种方法来实现这一点,而不会在更改发生时运行进程.因此,安装文件系统观察器对我来说并不是最佳选择.

Update2:存档位也不起作用,因为它与上次修改日期有同样的问题.将设置文件的存档位,但文件夹不会.

Answer 1

这篇文章 应该有帮助.基本上,您创建一个或多个通知对象,例如:

HANDLE dwChangeHandles[2]; 
dwChangeHandles[0] = FindFirstChangeNotification( 
      lpDir,                          // directory to watch 
      FALSE,                          // do not watch subtree 
      FILE_NOTIFY_CHANGE_FILE_NAME);  // watch file name changes 

   if (dwChangeHandles[0] == INVALID_HANDLE_VALUE) 
   {
     printf("\n ERROR: FindFirstChangeNotification function failed.\n");
     ExitProcess(GetLastError()); 
   }

// Watch the subtree for directory creation and deletion.  
   dwChangeHandles[1] = FindFirstChangeNotification( 
      lpDrive,                       // directory to watch 
      TRUE,                          // watch the subtree 
      FILE_NOTIFY_CHANGE_DIR_NAME);  // watch dir name changes 

   if (dwChangeHandles[1] == INVALID_HANDLE_VALUE) 
   {
     printf("\n ERROR: FindFirstChangeNotification function failed.\n");
     ExitProcess(GetLastError()); 
   }

然后你等待通知:

 while (TRUE) 
   { 
   // Wait for notification. 
      printf("\nWaiting for notification...\n");

      DWORD dwWaitStatus = WaitForMultipleObjects(2, dwChangeHandles, 
         FALSE, INFINITE); 

      switch (dwWaitStatus) 
      { 
         case WAIT_OBJECT_0: 

         // A file was created, renamed, or deleted in the directory.
         // Restart the notification. 
             if ( FindNextChangeNotification(dwChangeHandles[0]) == FALSE )
             {
               printf("\n ERROR: FindNextChangeNotification function failed.\n");
               ExitProcess(GetLastError()); 
             }
             break; 

         case WAIT_OBJECT_0 + 1: 

         // Restart the notification. 
             if (FindNextChangeNotification(dwChangeHandles[1]) == FALSE )
             {
               printf("\n ERROR: FindNextChangeNotification function failed.\n");
               ExitProcess(GetLastError()); 
             }
             break; 

         case WAIT_TIMEOUT:

         // A time-out occurred. This would happen if some value other 
         // than INFINITE is used in the Wait call and no changes occur.
         // In a single-threaded environment, you might not want an
         // INFINITE wait.

            printf("\nNo changes in the time-out period.\n");
            break;

         default: 
            printf("\n ERROR: Unhandled dwWaitStatus.\n");
            ExitProcess(GetLastError());
            break;
      }
   }
}