Descriptive monitor name from D3D display adapter ID - c++

Question

As the question suggests, I'm trying to pull a descriptive monitor name to match with a display adapter name. The code below gives me a device ID like \.\DISPLAY1 which is understandable but not what I'm looking for.
// Get name.
D3DADAPTER_IDENTIFIER9 d3dID;
d3d9.Get().GetAdapterIdentifier(iAdapter, 0, &d3dID);
dispAd.name = d3dID.Description;
// Add monitor ID to display adapter name.
FIX_ME // Not happy with this yet!
HMONITOR hMonitor = d3d9.Get().GetAdapterMonitor(iAdapter);
MONITORINFOEXA monInfoEx;
monInfoEx.cbSize = sizeof(MONITORINFOEXA);
if (GetMonitorInfoA(hMonitor, &monInfoEx))
{
dispAd.name = dispAd.name + " on: " + monInfoEx.szDevice;
}
else TPB_ASSERT(0); // Mute?
I've looked around the documentation for where to pull that actual name from but until now I haven't been able to find it. Sometimes I am a little stupid (or blind if you will), so I'll give it another go during my lunch break -- but perhaps someone can point me in the right direction? Thanks a lot.
(and by actual name I mean the one presented in the graphics configuration panel)

Answer 1

UINT iOutput = 0;
IDXGIOutput *pOutput = nullptr;
while (DXGI_ERROR_NOT_FOUND != pAdapter->EnumOutputs(iOutput++, &pOutput))
{
DXGI_OUTPUT_DESC desc;
VERIFY(S_OK == pOutput->GetDesc(&desc));
MONITORINFOEXW monInfoEx;
monInfoEx.cbSize = sizeof(MONITORINFOEXW);
GetMonitorInfoW(desc.Monitor, &monInfoEx);
DISPLAY_DEVICEW dispDev;
dispDev.cb = sizeof(DISPLAY_DEVICEW);
EnumDisplayDevicesW(monInfoEx.szDevice, 0, &dispDev, 0);
// FIXME: far from perfect, but should do the job if a vendor driver is installed.
// Otherwise it just displays something along the lines of "Plug & Play monitor".
SendDlgItemMessageW(hDialog, IDC_COMBO_OUTPUT, CB_ADDSTRING, 0, (LPARAM) dispDev.DeviceString);
pOutput->Release();
}

Answer 2

This works. It is supposed to need only Windows+stl to compile and eats HMONITOR. Some things I'm not happy with:
The WMI stuff assuming the monitor order is the same as EnumDisplayDevices(). I wanted to compare to the ID string but could not find it in the WMI data. Still needs another look.
The WMI code probably doesn't use the optimal name field but on the Netbook I have around right now all of them say "Plug & play" blabla so I'll have to test it on another system a soon as I get the chance. Just a matter of tuning this line in the WMI function, though:
pClassObj->Get(L"Description", 0, &varProp, NULL, NULL);
Code:
// tpbds -- Windows monitor description
// Disable warnings about non-unwindable objects in case C++ exceptions are disabled.
#pragma warning(disable:4530)
// Force Unicode.
#ifndef _UNICODE
#define _UNICODE
#endif
#define _WIN32_DCOM
#pragma comment(lib, "wbemuuid.lib")
#include <windows.h>
#include <comdef.h>
#include <wbemidl.h>
#include <string>
#include <sstream>
#include "monitordescription.h"
#define FIX_ME
#define SAFE_RELEASE(pX) if (pX) pX->Release(); pX = NULL;
// serialize constant value T to std::wstring
template<typename T> inline std::wstring ToWideString(const T &X)
{
std::wstringstream stream;
stream << X;
return stream.str();
}
static const std::wstring GetMonitorDescriptonFromWMI(DWORD iMonitor)
{
// If anything fails down the line I just return an empty string and apply a fallback mechanism.
// This type of function should never fail unless you're probing a non-existent piece of harwdare.
// Initialize COM.
if (FAILED(CoInitializeEx(NULL, COINIT_MULTITHREADED)))
{
return L"";
}
// Set COM security levels.
// Note: if you are using Windows 200, you need to specify the default authentication
// credentials for a user by using a SOLE_AUTHENTICATION_LIST structure in the pAuthList parameter.
if (FAILED(CoInitializeSecurity(
NULL,
-1,
NULL,
NULL,
RPC_C_AUTHN_LEVEL_DEFAULT,
RPC_C_IMP_LEVEL_IMPERSONATE,
NULL, // pAuthList
EOAC_NONE,
NULL)))
{
CoUninitialize();
return L"";
}
// Obtain initial locator to WMI.
IWbemLocator *pLocator = NULL;
if (FAILED(CoCreateInstance(CLSID_WbemLocator, NULL, CLSCTX_INPROC_SERVER, IID_IWbemLocator, reinterpret_cast<LPVOID *>(&pLocator))))
{
CoUninitialize();
return L"";
}
// Connect to WMI.
IWbemServices *pServices = NULL;
if (FAILED(pLocator->ConnectServer(_bstr_t(L"ROOT\\CIMV2"), NULL, NULL, NULL, NULL, NULL, NULL, &pServices)))
{
pLocator->Release();
CoUninitialize();
return NULL;
}
// Set security levels on the proxy.
if (FAILED(CoSetProxyBlanket(
pServices,
RPC_C_AUTHN_WINNT,
RPC_C_AUTHZ_NONE,
NULL,
RPC_C_AUTHN_LEVEL_CALL,
RPC_C_IMP_LEVEL_IMPERSONATE,
NULL,
EOAC_NONE)))
{
pServices->Release();
pLocator->Release();
CoUninitialize();
return L"";
}
// Request WMI data.
IEnumWbemClassObject* pEnumerator = NULL;
if (FAILED(pServices->ExecQuery(
bstr_t("WQL"),
bstr_t("SELECT * FROM Win32_DesktopMonitor"),
WBEM_FLAG_FORWARD_ONLY | WBEM_FLAG_RETURN_IMMEDIATELY,
NULL,
&pEnumerator)))
{
pServices->Release();
pLocator->Release();
CoUninitialize();
return L"";
}
// Try to compile a correct description.
std::wstring description;
DWORD iLoop = 1; // Monitor index is 1-based.
IWbemClassObject *pClassObj = NULL;
while (pEnumerator != NULL)
{
ULONG uReturn = 0;
const HRESULT hRes = pEnumerator->Next(WBEM_INFINITE, 1, &pClassObj, &uReturn);
if (uReturn == 0)
{
// Done (pClassObj remains NULL).
break;
}
// Is this the one we're looking for?
FIX_ME // Untested shortcut (assumes order is identical to that of EnumDisplayDevices).
if (iMonitor == iLoop)
{
FIX_ME // This needs to be tested, I only had a Netbook without proper driver!
VARIANT varProp;
pClassObj->Get(L"Description", 0, &varProp, NULL, NULL); // Check the MSDN for Win32_DesktopMonitor to see what your options are!
description = varProp.bstrVal;
description += L" #" + ToWideString(iMonitor);
VariantClear(&varProp);
SAFE_RELEASE(pClassObj);
// Done.
break;
}
else
SAFE_RELEASE(pClassObj);
}
pServices->Release();
pLocator->Release();
CoUninitialize();
// With a bit of luck this string was just built.
return description;
}
const std::wstring GetMonitorDescription(HMONITOR hMonitor)
{
MONITORINFOEX monInfoEx;
monInfoEx.cbSize = sizeof(MONITORINFOEX);
if (GetMonitorInfo(hMonitor, &monInfoEx))
{
// Get monitor index by matching ID.
DWORD iDevNum = 0;
DISPLAY_DEVICE dispDev;
do
{
dispDev.cb = sizeof(DISPLAY_DEVICE);
EnumDisplayDevices(NULL, iDevNum, &dispDev, 0);
++iDevNum; // Incrementing here is right since we want a 1-based display.
}
while (0 != wcscmp(dispDev.DeviceName, monInfoEx.szDevice));
// Attempt to get the description from WMI.
// If it's empty, carry on.
const std::wstring descriptionFromWMI = GetMonitorDescriptonFromWMI(iDevNum);
if (!descriptionFromWMI.empty())
return descriptionFromWMI;
// Enumerate again, since doing it by string instead of index yields a different (more usable) DeviceString.
dispDev.cb = sizeof(DISPLAY_DEVICE);
EnumDisplayDevices(monInfoEx.szDevice, 0, &dispDev, 0);
// WMI approach failed so we rely on EnumDisplayDevices() for an acceptable result.
std::wstring description(dispDev.DeviceString);
return description + L" #" + ToWideString(iDevNum);
}
else return L"Unknown monitor";
}