VC++文件监控(一) ReadDirectoryChangesW

VC++实施文件监控：实例和详解

相关帮助: http://hi.baidu.com/jiahaosoft/blog/item/b441d1218eebece0d6cae274.html

我这里只介绍采用ReadDirectoryChangesW对文件目录实施监控

关键代码

CfgdsgDlg * dlg = (CfgdsgDlg*)lparam;

	HANDLE hDir; 
	char notify[1024]; 
	DWORD cbBytes,i; 
	char AnsiChar[3]; 
	wchar_t UnicodeChar[2]; 
	CString path;

	FILE_NOTIFY_INFORMATION *pnotify=(FILE_NOTIFY_INFORMATION *)notify; 
	FILE_NOTIFY_INFORMATION *tmp; 

	GetCurrentDirectory(MAX_PATH,path.GetBuffer(MAX_PATH+1));
	hDir = CreateFile( path, FILE_LIST_DIRECTORY,
		FILE_SHARE_READ | 
		FILE_SHARE_WRITE | 
		FILE_SHARE_DELETE, NULL, 
		OPEN_EXISTING, FILE_FLAG_BACKUP_SEMANTICS | 
		FILE_FLAG_OVERLAPPED, NULL); 
	if (hDir == INVALID_HANDLE_VALUE) 
	{ 

		dlg->m_edit.ReplaceSel("hDir:INVALID_HANDLE_VALUE\r\n");
		return 0;
	} 

	while (TRUE) 
	{ 
		if(ReadDirectoryChangesW(hDir, &notify, sizeof(notify),
			FALSE, FILE_NOTIFY_CHANGE_FILE_NAME| FILE_NOTIFY_CHANGE_LAST_WRITE, 
			&cbBytes, NULL, NULL)) 
		{ 

			tmp = pnotify; 

			switch(tmp->Action) 
			{ 
			case FILE_ACTION_ADDED: 

				dlg->m_edit.ReplaceSel("Directory/File added （添加文件）- \r\n");
				break; 
			case FILE_ACTION_REMOVED:
				dlg->m_edit.ReplaceSel("Directory/File removed （删除文件）- \r\n");
				break; 
			case FILE_ACTION_MODIFIED: 
				dlg->m_edit.ReplaceSel("Directory/File modified （修改文件内容）- \r\n");
				break; 
			case FILE_ACTION_RENAMED_OLD_NAME: 
				dlg->m_edit.ReplaceSel("Directory/File old name （修改文件名字）- \r\n");
				break; 
			case FILE_ACTION_RENAMED_NEW_NAME: 
				dlg->m_edit.ReplaceSel("Directory/File new name - \r\n");
				break; 
			default: 
				break; 
			}
		}
	}

　　

FILE_NOTIFY_INFORMATION //可以确定是那个文件进行的修改

typedef struct _FILE_NOTIFY_INFORMATION {
  DWORD NextEntryOffset;
  DWORD Action;//动作
  DWORD FileNameLength;//文件名字的长度
  WCHAR FileName[1];//文件名字
} FILE_NOTIFY_INFORMATION,
*PFILE_NOTIFY_INFORMATION;

ReadDirectoryChangesW 返回类型(见MSDN)

Value	Meaning
FILE_ACTION_ADDED 0x00000001	The file was added to the directory.
FILE_ACTION_REMOVED 0x00000002	The file was removed from the directory.
FILE_ACTION_MODIFIED 0x00000003	The file was modified. This can be a change in the time stamp or attributes.
FILE_ACTION_RENAMED_OLD_NAME 0x00000004	The file was renamed and this is the old name.
FILE_ACTION_RENAMED_NEW_NAME 0x00000005	The file was renamed and this is the new name.

效果如下：

不足的地方:

只能检测到指定目录和下一级目录，超过目录级数，该函数检测不到。