请教关于获取NVIDIA独显硬件ID问题

// Example code to retrieve vendor and device ID's for the primary display    

// device.    

//    

// NOTE: Visual Studio 6 does not ship with a winuser.h that defines the    

//       EnumDisplayDevices function so in order to compile this code, you'll     

//       need to install the Platform SDK.     

#include "stdafx.h"

#include <windows.h>    



#include <string>    

#include <iostream>    



using namespace std;   



bool GetDeviceIdentification(string &vendorID, string &deviceID)   

{   

	DISPLAY_DEVICE dd;   

	dd.cb = sizeof(DISPLAY_DEVICE);   



	int i = 0;   

	string id;   



	// locate primary display device    

	while (EnumDisplayDevices(NULL, i, &dd, 0))   

	{   

		if (dd.StateFlags & DISPLAY_DEVICE_PRIMARY_DEVICE)

		{   

			id = dd.DeviceID;

			break;   

		}   

		i++;   

	}   



	if (id == "") return false;   



	// get vendor ID    

	vendorID = id.substr(8, 4);   



	// get device ID    

	deviceID = id.substr(17, 4);   



	return true;   

}   



int main(void)   

{   

	string vendorID;   

	string deviceID;   



	if (GetDeviceIdentification(vendorID, deviceID))   

	{   

		cout << "Vendor ID: " << vendorID << endl;   

		cout << "Device ID: " << deviceID << endl;   

	}   

	else   

		cout << "Unable to locate device information" << endl;   

	cin.get();



	return 0;   

}