Deleting a Standard TCP IP port using xcvdata not working - c++

Question

Xcvdata() for deleting port.
BOOL DeletePortCus( TCHAR* PortName )
{
HANDLE hPrinter;
PRINTER_DEFAULTS PrinterDefaults;
memset(&PrinterDefaults, 0, sizeof(PrinterDefaults));
PrinterDefaults.pDatatype = NULL;
PrinterDefaults.pDevMode = NULL;
PrinterDefaults.DesiredAccess = SERVER_ACCESS_ADMINISTER;
DWORD needed = 0;
DWORD rslt = 0;
//Port data
PORT_DATA_1 pOutputData ;
DWORD error = 0;
if (!OpenPrinter(L",XcvMonitor Standard TCP/IP Port", &hPrinter, &PrinterDefaults))
{
LPVOID lpMsgBuf;
FormatMessage(FORMAT_MESSAGE_ALLOCATE_BUFFER | FORMAT_MESSAGE_FROM_SYSTEM | FORMAT_MESSAGE_IGNORE_INSERTS,
NULL, GetLastError(), NULL,(LPTSTR) &lpMsgBuf, 0, NULL );
_tprintf( TEXT("Error in OpenPrinter. Error msg : %s"),lpMsgBuf);
LocalFree( lpMsgBuf );
return FALSE;
}
DWORD xcvresult= 0;
if (
!XcvData(
hPrinter,
TEXT("DeletePort"),
(PBYTE)PortName,
(lstrlen(PortName) +1) * sizeof(TCHAR), //the 1 is for the trailing NULL
( byte * ) &pOutputData,
sizeof(PORT_DATA_1),
&needed,
&xcvresult)
)
{
LPVOID lpMsgBuf;
FormatMessage(FORMAT_MESSAGE_ALLOCATE_BUFFER | FORMAT_MESSAGE_FROM_SYSTEM | FORMAT_MESSAGE_IGNORE_INSERTS,
NULL, GetLastError(), NULL,(LPTSTR) &lpMsgBuf, 0, NULL );
_tprintf( TEXT("Error in XcvData. Error msg : %s; XcvDataPort status val = %d"), lpMsgBuf, xcvresult);
LocalFree( lpMsgBuf );
return FALSE;
}
ClosePrinter(hPrinter);
return TRUE;
}
The highlight is both the functions (openprinter and xcvdata) succeed. But the port is not getting removed. I am completely at a loss here as I dont have any error to lookup.
Instead of ,XcvMonitor Standard TCP/IP Port I also tried with ,XcvPort <portname>. Still same.
As Samer suggested below, I tried with OpenPrinter2 with no cache option.
PS: I know there's this simple alternative DeletePort(), but it invokes a UI dialog box if it fails, so I don't want to use it.

Answer 1

It seems the issue might be related to specific version of OS which caches printer handles. To get around this you use an alternate call OpenPrinter2 with the PRINTER_OPTION_NO_CACHE. Below is the modified code with the flag set.
HANDLE hPrinter;
PRINTER_DEFAULTS PrinterDefaults;
memset(&PrinterDefaults, 0, sizeof(PrinterDefaults));
PrinterDefaults.pDatatype = NULL;
PrinterDefaults.pDevMode = NULL;
PrinterDefaults.DesiredAccess = SERVER_ACCESS_ADMINISTER;
PRINTER_OPTIONS PrinterOptions;
PrinterOptions.cbSize = sizeof(PrinterOptions);
PrinterOptions.dwFlags = PRINTER_OPTION_NO_CACHE;
DWORD needed = 0;
DWORD rslt = 0;
//Port data
PORT_DATA_1 pOutputData ;
DWORD error = 0;
if (!OpenPrinter2(L",XcvMonitor Standard TCP/IP Port", &hPrinter, &PrinterDefaults, &PrinterOptions))
{
LPVOID lpMsgBuf;