How to refresh only one time in ReadDirectoryChange in WIN32 API? - winapi

Question

I use ReadDirectoryChange in WIN32 API. After I copy 10 folder, my program is running refresh 10 times. However I only want it refresh once.
Can you help me? Here is my code:
bool FolderWatcher::Loop ()
{
// declare a variable and using it to return
int i = 0;
// convert from WCHAR to LPWSTR
LPWSTR ptr = _folder;
char buf[256 * (sizeof(FILE_NOTIFY_INFORMATION) + MAX_PATH * sizeof(WCHAR))] = {0};
DWORD bytesReturned = 0;
BOOL result = FALSE;
FILE_NOTIFY_INFORMATION *fni = NULL;
// using CreateFile to choose folder need to watch
HANDLE hDir = CreateFileW(
ptr,
FILE_LIST_DIRECTORY |
STANDARD_RIGHTS_READ,
//Enables subsequent open operations on a file or device to request read access.
FILE_SHARE_READ |
//Enables subsequent open operations on a file or device to request write access.
FILE_SHARE_WRITE |
//Enables subsequent open operations on a file or device to request delete access.
FILE_SHARE_DELETE,
NULL,
//Opens a file or device, only if it exists.
OPEN_EXISTING,
FILE_FLAG_BACKUP_SEMANTICS,
NULL);
// check if directory is not exists
if (!hDir || hDir == INVALID_HANDLE_VALUE)
{
i = 0;
}
else
{
for (;;)
{
// call ReadDirectoryChangeW to watch folder
result = ReadDirectoryChangesW(hDir,
buf,
sizeof(buf) / sizeof(*buf),
FALSE, /* monitor the entire subtree */
FILE_NOTIFY_CHANGE_FILE_NAME |
FILE_NOTIFY_CHANGE_DIR_NAME |
FILE_NOTIFY_CHANGE_ATTRIBUTES |
FILE_NOTIFY_CHANGE_SIZE |
/*FILE_NOTIFY_CHANGE_LAST_WRITE |
FILE_NOTIFY_CHANGE_LAST_ACCESS |*/
FILE_NOTIFY_CHANGE_CREATION |
FILE_NOTIFY_CHANGE_SECURITY,
&bytesReturned,
NULL,
NULL);
if (result && bytesReturned)
{
wchar_t filename[MAX_PATH];
wchar_t action[256];
for (fni = (FILE_NOTIFY_INFORMATION*)buf; fni; )
{
switch (fni->Action)
{
// excute if a folder/ text docu is added
case FILE_ACTION_ADDED:
{
i = 1;
PostMessage (_hwndNotifySink, WM_FOLDER_CHANGE, 0, (LPARAM) _folder);
}
break;
// excute if a folder/ text docu is removed
case FILE_ACTION_REMOVED:
{
i = 1;
PostMessage (_hwndNotifySink, WM_FOLDER_CHANGE, 0, (LPARAM) _folder);
}
break;
case FILE_ACTION_MODIFIED:
{
i = 1;
if(lstrcmp(fni->FileName, L"service.log") != 0)
PostMessage (_hwndNotifySink, WM_FOLDER_CHANGE, 0, (LPARAM) _folder);
break;
}
// excute if a folder/ text docu is renamed
case FILE_ACTION_RENAMED_OLD_NAME:
{
i = 1;
PostMessage (_hwndNotifySink, WM_FOLDER_CHANGE, 0, (LPARAM) _folder);
break;
}
// excute if a folder/ text docu is renamed new name
case FILE_ACTION_RENAMED_NEW_NAME:
{
i = 1;
PostMessage (_hwndNotifySink, WM_FOLDER_CHANGE, 0, (LPARAM) _folder);
}
break;
}
if (fni->NextEntryOffset)
{
char *p = (char*)fni;
fni = (FILE_NOTIFY_INFORMATION*)(p + fni->NextEntryOffset);
}
else
{
fni = NULL;
}
}
}
else
{
i = 0;
}
}
CloseHandle(hDir); // close handle
}
return i; // return value of i
}
In case WM_FOLDER_CHANGE, I call refresh function.