Get information about device using SetupAPI - c++

Question

I have a printer connected with USB port and I want to get some information about it. I am using SetupDiEnumDeviceInfo function from setupapi to get information. I am doing everything as it is described in MSDN.
#include <string>
#include <windows.h>
#include <vector>
#include <iostream>
#include <setupapi.h>
#include <winerror.h>
#pragma comment (lib, "SetupAPI.lib")
static GUID GUID_DEVCLASS_PORTS = { 0x4d36e978, 0xe325, 0x11ce, 0xbf, 0xc1, 0x08, 0x00, 0x2b, 0xe1, 0x03, 0x18 };
int main()
{
SP_DEVINFO_DATA devInfoData;
HDEVINFO deviceInfo = SetupDiGetClassDevs(&GUID_DEVCLASS_PORTS, 0, 0, DIGCF_PRESENT);
devInfoData.cbSize = sizeof(SP_DEVINFO_DATA);
DWORD nDevice = 0;
if (SetupDiEnumDeviceInfo(deviceInfo, nDevice, &devInfoData))
{
}
return 0;
}
The problem is that I am always getting false result.
GetLastError() function retruns 259.
What am I doing wrong?

Answer 1

this is my sample. I add the devguid.h, and use GUID_DEVCLASS_USB.
#include <string>
#include <windows.h>
#include <setupapi.h>
#include <devguid.h>
#pragma comment (lib, "SetupAPI.lib")
int main()
{
int res = 0;
HDEVINFO hDevInfo;
SP_DEVINFO_DATA DeviceInfoData = { sizeof(DeviceInfoData) };
// get device class information handle
hDevInfo = SetupDiGetClassDevs(&GUID_DEVCLASS_USB, 0, 0, DIGCF_PRESENT);
if (hDevInfo == INVALID_HANDLE_VALUE)
{
res = GetLastError();
return res;
}
// enumerute device information
DWORD required_size = 0;
for (int i = 0; SetupDiEnumDeviceInfo(hDevInfo, i, &DeviceInfoData); i++)
{
DWORD DataT;
char friendly_name[2046] = { 0 };
DWORD buffersize = 2046;
DWORD req_bufsize = 0;
// get device description information
if (!SetupDiGetDeviceRegistryPropertyA(hDevInfo, &DeviceInfoData, SPDRP_CLASSGUID, &DataT, (PBYTE)friendly_name, buffersize, &req_bufsize))
{
res = GetLastError();
continue;
}
char temp[512] = { 0 };
sprintf_s(temp, 512, "USB device %d: %s", i, friendly_name);
puts(temp);
}
return 0;
}