QueryBus | Documentation

QueryBus: QueryBus sends request to get complete information from the virtual serial bus installed by VSPD.

BOOL QueryBus(
	void* inBuffer,	// pointer to buffer
	long sizeInBuffer,	// size of buffer
	void* OutBuffer,	// pointer to buffer
	long sizeOutBuffer,	// size of buffer
);

Parameters:

InBuffer

A pointer to VSBUS_QUERY or VSBUS_QUERY_EX structures. If you want to get information about all current virtual serial ports then use VSBUS_QUERY structure and if you want to get extended information about single virtual serial pair then use VSBUS_QUERY_EX structure.

OutBuffer

A pointer to either PORT_INFORMATION or PORT_INFORMATION_EX structures list. If you have used VSBUS_QUERY than you should get PORT_INFORMATION list and if you used VSBUS_QUERY_EX then you should get PORT_INFORMATION_EX.

Return values:

CreatePair returns TRUE if virtual serial pair was created successfully and FALSE otherwise

Code example:

Getting information about all virtual serial ports

void		*Buffer;
long		sizeBuffer;
			
Query.Size = sizeof (VSBUS_QUERY);
Query.QueryType = QUERYTYPE_PORTS;
Buffer = new char[sizeBuffer];
				
			
	while (!QueryBus(&Query, Query.Size, Buffer, sizeBuffer)) {
				
	if (GetLastError() != ERROR_INSUFFICIENT_BUFFER)
		{
			delete[] Buffer;
			return;
				
		}
		else
		  {
			delete[] Buffer;
			   sizeBuffer = sizeBuffer * 2;			
			   Buffer = new char[sizeBuffer];
		}
}
			
PPORT_INFORMATION	portInfo = (PPORT_INFORMATION)Buffer;
			
while (portInfo->NextOffset != 0) 
	{
		if (portInfo->NameOffset != 0)
		{
			CString portName((PWCHAR)((ULONG)portInfo + portInfo->NameOffset));
			printf ("%s\n", portName);
		}
			
		portInfo = (PPORT_INFORMATION)((ULONG)portInfo + portInfo->NextOffset);
	} 
delete[] Buffer;

Getting information about a single port

void		*Buffer;
int		iSize = 1024;
VSBUS_QUERY_EX	Query;
PPORT_INFORMATION_EX portInfo;
	
	
Query.Size = sizeof (VSBUS_QUERY_EX);
Query.QueryType = QUERYINFO_PAIR;
mbstowcs (Query.PortName, "COM5", MAX_PORTNAME_LEN);
	
Buffer = new char [iSize];
	
while (!QueryBus(&Query, Query.Size, Buffer, iSize)) {
	{
		if (GetLastError() != ERROR_INSUFFICIENT_BUFFER)
		{
			delete[] Buffer;
			   return;
		}
		else
		{
			iSize *= 2;
			delete[] Buffer;
		    Buffer = new char [iSize];
		}
	}
	
while (portInfo->NextOffset != 0) 
{
	if (portInfo->NameOffset != 0) 
	{
		CString portName((PWCHAR)((ULONG)portInfo + portInfo->NameOffset));
		printf ("%s send - %d recv - %d\n", portName, portInfo->TxCount, portInfo->RxCount);
	}
	
	portInfo = (PPORT_INFORMATION_EX)((ULONG)portInfo + portInfo->NextOffset);
} 
	
portInfo = (PPORT_INFORMATION_EX)Buffer;
delete[] Buffer;