请问如何用纯API函数和createfile打开guid设备？

我要在delphi中使用api函数打开我的WDM驱动并用devicecontrol进行控制，ds提供的openbyinterface好像太复杂了，还用到了CDeviceInterfaceClass和CDeviceInterface类，请大佬指点！

这个很通用啦，instance取0就好了。SetupApi.h和SetupApi.Lib

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);
while(!SetupDiEnumDeviceInterfaces(info, NULL, pGuid, instance, &ifdata))
{
if(GetLastError()==ERROR_NO_MORE_ITEMS)
{
printf(\"No SP_INTERFACE_DEVICE_DATA available for this GUID instance\\n\");
SetupDiDestroyDeviceInfoList(info);
return NULL;
}
else
{
instance++;
}
}

// 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 | FILE_FLAG_OVERLAPPED,
NULL);
if( rv==INVALID_HANDLE_VALUE)
{
rv = NULL;
}
delete ifDetail;
SetupDiDestroyDeviceInfoList(info);
return rv;
}