一个小白问题，如何获得USB设备名?

#include <setupapi.h>   

#pragma comment(lib, "setupapi.lib")



const GUID GUID_DEVINTERFACE_DISPLAY_ADAPTER = { 0x5b45201d, 0xf2f2, 0x4f3b, { 0x85, 0xbb,  0x30,  0xff,  0x1f,  0x95,  0x35,  0x99 } };







long GetDisplayDeviceInfo(unsigned long nAdapterIndex, tagI2CDeviceStruct* pobjI2CDevice)

{

	pobjI2CDevice->nDisplayDeviceLength = 0;



	HDEVINFO hDevInfoX = SetupDiGetClassDevs(&GUID_DEVINTERFACE_DISPLAY_ADAPTER, NULL, 0, DIGCF_PRESENT | DIGCF_DEVICEINTERFACE); 

	if (hDevInfoX == INVALID_HANDLE_VALUE)   

	{   

		//printf("Failed to get device handle. Error[%d]", GetLastError());   

		return DVDC_ERR_GET_CLASS_DEV;   

	}   





	SP_DEVINFO_DATA DeviceInfoData;   

	//DWORD dwDeviceIndex;   



	// Enumerate through all devices in Set.   

	DeviceInfoData.cbSize = sizeof(SP_DEVINFO_DATA);   

	if (!SetupDiEnumDeviceInfo(hDevInfoX, nAdapterIndex, &DeviceInfoData))   

	{ 

		SetupDiDestroyDeviceInfoList(hDevInfoX); 

		if (GetLastError() == ERROR_NO_MORE_ITEMS) 

			return DVDC_ERR_NOT_FOUND_DISPLAY_ADAPTER; 

		else

			return DVDC_ERR_FIND_DISPLAY_ADAPTER; 

	} 



	DWORD   DataT = 0;   

	DWORD   buffersize   =   0; 

	LPTSTR   buffer   =   NULL;   



	while(!SetupDiGetDeviceRegistryProperty(   

		hDevInfoX,   

		&DeviceInfoData,   

		SPDRP_PHYSICAL_DEVICE_OBJECT_NAME,   

		&DataT,   

		(PBYTE)buffer,   

		buffersize,   

		&buffersize))   

	{   

		if (GetLastError() == ERROR_INSUFFICIENT_BUFFER)   

		{   

			//   Change   the   buffer   size.   

			if (buffer)   

				LocalFree(buffer);   

			buffer = (LPTSTR)LocalAlloc(LPTR,buffersize);   

		}   

		else   

		{   

			printf("Failed to get device guid. Error[%d] \n", GetLastError());   

			break;   

		}   

	}   



	if (buffer)   

	{

#ifdef _UNICODE

		int iMultiBytesLength = WideCharToMultiByte ( 

			CP_ACP,					// ANSI 代码页                          

			WC_COMPOSITECHECK,		// 检查重音字符                          

			buffer,			// 原Unicode 串                          

			-1,						// -1 意思是串以0x00结尾                          

			NULL,					// 目的char字符串                          

			0,						// 缓冲大小                          

			NULL,					// 肥缺省字符串                          

			NULL);					// 忽略这个参数



		if (iMultiBytesLength <= 0)

		{

			SetupDiDestroyDeviceInfoList(hDevInfoX); 

			return DVDC_ERR_GET_DEVICE_PATH_LENGTH; 

		}



		if (iMultiBytesLength > sizeof(pobjI2CDevice->pcDisplayDevicePath))

		{

			SetupDiDestroyDeviceInfoList(hDevInfoX); 

			return DVDC_ERR_DEVICE_PATH_LENGTH_SMALL; 

		}



		WideCharToMultiByte ( 

			CP_ACP,						// ANSI 代码页                          

			WC_COMPOSITECHECK,			// 检查重音字符                          

			buffer,				// 原Unicode 串                          

			-1,							// -1 意思是串以0x00结尾                          

			pobjI2CDevice->pcDisplayDevicePath,			// 目的char字符串                          

			iMultiBytesLength,			// 缓冲大小                          

			NULL,						// 肥缺省字符串                          

			NULL);						// 忽略这个参数



		//printf("  path:[%s]\n", pcResult);   

		pobjI2CDevice->nDisplayDeviceLength = iMultiBytesLength;

#else

		//MessageBox(NULL, "not unicode", "xxxx", MB_OK);

		if ((strlen(buffer) + 1) > sizeof(pobjI2CDevice->pcDisplayDevicePath))

		{

			SetupDiDestroyDeviceInfoList(hDevInfoX); 

			return DVDC_ERR_DEVICE_PATH_LENGTH_SMALL; 

		}



		pobjI2CDevice->nDisplayDeviceLength = strlen(buffer) + 1;

		strcpy_s(pobjI2CDevice->pcDisplayDevicePath, sizeof(pobjI2CDevice->pcDisplayDevicePath), buffer);

		pobjI2CDevice->pcDisplayDevicePath[pobjI2CDevice->nDisplayDeviceLength] = 0;

#endif

	}



	// Cleanup   

	SetupDiDestroyDeviceInfoList(hDevInfoX);   





	return DVDC_ERR_SUCCESS;

}