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序号：29654 发表者：worm 发表日期：2003-02-11 02:04:35
<br>主题：如何监视某个文件夹中的文件状态？
<br>内容：如此文件夹中是否有文件正在写入，或文件是否正被改写等。
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<font color=red>答案被接受</font><br>回复者：bb 回复日期：2003-02-11 09:05:10
<br>内容：方法一<BR>Monitoring Changes in a Directory or Directory Tree<BR><BR>The following example monitors the directory tree starting at C:\ for directory name changes. It also monitors the C:\WINDOWS directory for file name changes. <BR><BR>The example uses the FindFirstChangeNotification function to create two notification handles and the WaitForMultipleObjects function to wait on the handles. Whenever a directory is created or deleted in the tree starting at C:\ , the example updates the entire directory tree. Whenever a file is created or deleted in the C:\WINDOWS directory, the example refreshes the WINDOWS directory. The FindNextChangeNotification function restarts the change notification each time the example processes a change. <BR><BR>DWORD dwWaitStatus; <BR>HANDLE dwChangeHandles[2]; <BR> <BR>// Watch the C:\WINDOWS directory for file creation and <BR>// deletion. <BR> <BR>dwChangeHandles[0] = FindFirstChangeNotification( <BR>&nbsp;&nbsp;&nbsp;&nbsp;"C:\\WINDOWS",&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; // directory to watch <BR>&nbsp;&nbsp;&nbsp;&nbsp;FALSE,&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; // do not watch the subtree <BR>&nbsp;&nbsp;&nbsp;&nbsp;FILE_NOTIFY_CHANGE_FILE_NAME); // watch file name changes <BR> <BR>if (dwChangeHandles[0] == INVALID_HANDLE_VALUE) <BR>&nbsp;&nbsp;&nbsp;&nbsp;ExitProcess(GetLastError()); <BR> <BR>// Watch the C:\ subtree for directory creation and <BR>// deletion. <BR> <BR>dwChangeHandles[1] = FindFirstChangeNotification( <BR>&nbsp;&nbsp;&nbsp;&nbsp;"C:\\",&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;// directory to watch <BR>&nbsp;&nbsp;&nbsp;&nbsp;TRUE,&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;// watch the subtree <BR>&nbsp;&nbsp;&nbsp;&nbsp;FILE_NOTIFY_CHANGE_DIR_NAME);&nbsp;&nbsp;// watch dir. name changes <BR> <BR>if (dwChangeHandles[1] == INVALID_HANDLE_VALUE) <BR>&nbsp;&nbsp;&nbsp;&nbsp;ExitProcess(GetLastError()); <BR> <BR>// Change notification is set. Now wait on both notification <BR>// handles and refresh accordingly. <BR> <BR>while (TRUE) <BR>{ <BR> <BR>&nbsp;&nbsp;&nbsp;&nbsp;// Wait for notification.<BR> <BR>&nbsp;&nbsp;&nbsp;&nbsp;dwWaitStatus = WaitForMultipleObjects(2, dwChangeHandles, <BR>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;FALSE, INFINITE); <BR> <BR>&nbsp;&nbsp;&nbsp;&nbsp;switch (dwWaitStatus) <BR>&nbsp;&nbsp;&nbsp;&nbsp;{ <BR>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;case WAIT_OBJECT_0: <BR> <BR>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;// A file was created or deleted in C:\WINDOWS. <BR>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;// Refresh this directory and restart the <BR>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;// change notification. RefreshDirectory is an <BR>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;// application-defined function. <BR> <BR>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;RefreshDirectory("C:\\WINDOWS") <BR>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;if ( FindNextChangeNotification( <BR>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;dwChangeHandles[0]) == FALSE ) <BR>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;ExitProcess(GetLastError()); <BR>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;break; <BR> <BR>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;case WAIT_OBJECT_0 + 1: <BR> <BR>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;// A directory was created or deleted in C:\. <BR>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;// Refresh the directory tree and restart the <BR>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;// change notification. RefreshTree is an <BR>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;// application-defined function. <BR> <BR>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;RefreshTree("C:\\"); <BR>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;if (FindNextChangeNotification( <BR>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;dwChangeHandles[1]) == FALSE) <BR>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;ExitProcess(GetLastError()); <BR>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;break; <BR> <BR>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;default: <BR>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;ExitProcess(GetLastError()); <BR>&nbsp;&nbsp;&nbsp;&nbsp;} <BR>} <BR>
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回复者：bb 回复日期：2003-02-11 09:10:10
<br>内容：方法二<BR><BR>Windows NT 3.5+sp3以上（win95/98不支持）<BR><BR>BOOL ReadDirectoryChangesW(<BR>&nbsp;&nbsp;HANDLE hDirectory,&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;// handle to directory<BR>&nbsp;&nbsp;LPVOID lpBuffer,&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;// read results buffer<BR>&nbsp;&nbsp;DWORD nBufferLength,&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;// length of buffer<BR>&nbsp;&nbsp;BOOL bWatchSubtree,&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; // monitoring option<BR>&nbsp;&nbsp;DWORD dwNotifyFilter,&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; // filter conditions<BR>&nbsp;&nbsp;LPDWORD lpBytesReturned,&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;// bytes returned<BR>&nbsp;&nbsp;LPOVERLAPPED lpOverlapped,&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;// overlapped buffer<BR>&nbsp;&nbsp;LPOVERLAPPED_COMPLETION_ROUTINE lpCompletionRoutine // completion routine<BR>);<BR>
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