Monitoring Changes in a Directory or Directory Tree

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.

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.

DWORD dwWaitStatus; 
HANDLE dwChangeHandles[2]; 
 
// Watch the C:\WINDOWS directory for file creation and 
// deletion. 
 
dwChangeHandles[0] = FindFirstChangeNotification( 
    "C:\\WINDOWS",                 // directory to watch 
    FALSE,                         // do not watch the subtree 
    FILE_NOTIFY_CHANGE_FILE_NAME); // watch file name changes 
 
if (dwChangeHandles[0] == INVALID_HANDLE_VALUE) 
    ExitProcess(GetLastError()); 
 
// Watch the C:\ subtree for directory creation and 
// deletion. 
 
dwChangeHandles[1] = FindFirstChangeNotification( 
    "C:\\",                        // directory to watch 
    TRUE,                          // watch the subtree 
    FILE_NOTIFY_CHANGE_DIR_NAME);  // watch dir. name changes 
 
if (dwChangeHandles[1] == INVALID_HANDLE_VALUE) 
    ExitProcess(GetLastError()); 
 
// Change notification is set. Now wait on both notification 
// handles and refresh accordingly. 
 
while (TRUE) 
{ 
 
    // Wait for notification.
 
    dwWaitStatus = WaitForMultipleObjects(2, dwChangeHandles, 
        FALSE, INFINITE); 
 
    switch (dwWaitStatus) 
    { 
        case WAIT_OBJECT_0: 
 
        // A file was created or deleted in C:\WINDOWS. 
        // Refresh this directory and restart the 
        // change notification. RefreshDirectory is an 
        // application-defined function. 
 
            RefreshDirectory("C:\\WINDOWS") 
            if ( FindNextChangeNotification( 
                    dwChangeHandles[0]) == FALSE ) 
                ExitProcess(GetLastError()); 
            break; 
 
        case WAIT_OBJECT_0 + 1: 
 
        // A directory was created or deleted in C:\. 
        // Refresh the directory tree and restart the 
        // change notification. RefreshTree is an 
        // application-defined function. 
 
            RefreshTree("C:\\"); 
            if (FindNextChangeNotification( 
                    dwChangeHandles[1]) == FALSE) 
                ExitProcess(GetLastError()); 
            break; 
 
        default: 
            ExitProcess(GetLastError()); 
    } 
}