主要用到的API函数:
Public Declare Function FindFirstChangeNotification Lib "kernel32" Alias "FindFirstChangeNotificationA" (ByVal lpPathName As String, ByVal bWatchSubtree As Long, ByVal dwNotifyFilter As Long) As Long
Public Declare Function FindCloseChangeNotification Lib "kernel32" (ByVal hChangeHandle As Long) As Long
Public Declare Function FindNextChangeNotification Lib "kernel32" (ByVal hChangeHandle As Long) As Long
具体的使用请google之。