设备安装问题?

怎么从程序里用SETUPAPI来判断我的设备是否已经接入计算机了?

能说详细点吗,最好给个例子...

HANDLE GetDeviceViaInterface( GUID* pGuid, DWORD instance)
{

// Get handle to relevant device information set
HDEVINFO info = SetupDiGetClassDevs(pGuid, NULL, NULL, DIGCF_PRESENT | DIGCF_INTERFACEDEVICE);
if(info==INVALID_HANDLE_VALUE)
{
printf("No HDEVINFO available for this GUID\n");
return NULL;
}

// Get interface data for the requested instance
SP_INTERFACE_DEVICE_DATA ifdata;
ifdata.cbSize = sizeof(ifdata);
if(!SetupDiEnumDeviceInterfaces(info, NULL, pGuid, instance, &ifdata))
{
printf("No SP_INTERFACE_DEVICE_DATA available for this GUID instance\n");
SetupDiDestroyDeviceInfoList(info);
return NULL;
}

// Get size of symbolic link name
DWORD ReqLen;
SetupDiGetDeviceInterfaceDetail(info, &ifdata, NULL, 0, &ReqLen, NULL);
PSP_INTERFACE_DEVICE_DETAIL_DATA ifDetail = (PSP_INTERFACE_DEVICE_DETAIL_DATA)(new char[ReqLen]);
if( ifDetail==NULL)
{
SetupDiDestroyDeviceInfoList(info);
return NULL;
}

// Get symbolic link name
ifDetail->cbSize = sizeof(SP_INTERFACE_DEVICE_DETAIL_DATA);
if( !SetupDiGetDeviceInterfaceDetail(info, &ifdata, ifDetail, ReqLen, NULL, NULL))
{
SetupDiDestroyDeviceInfoList(info);
delete ifDetail;
return NULL;
}

printf("Symbolic link is %s\n",ifDetail->DevicePath);
// Open file
HANDLE rv = CreateFile( ifDetail->DevicePath,
GENERIC_READ | GENERIC_WRITE,
FILE_SHARE_READ | FILE_SHARE_WRITE,
NULL, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, NULL);
if( rv==INVALID_HANDLE_VALUE) rv = NULL;

delete ifDetail;
SetupDiDestroyDeviceInfoList(info);
return rv;
}

---------------------
用以上的代码，只要代入你的GUID就可以知道是否有设备接入了！

请问两个参数的意思?

我只知道设备类,和设备的ID,它不提供INTERFACE,怎么找?

设备ID是指什么？？？

就是VERDOR_ID和PRODUCT_ID, 这个设备没有接口...