MonitorInfo, using Microsoft.WIndows.CsWin32

MonitorInfo.cs

using System.Runtime.InteropServices;
using Windows.Win32;
using Windows.Win32.Devices.Display;
using Windows.Win32.Foundation;

const int QDC_ONLY_ACTIVE_PATHS = 2;
const int ERROR_INSUFFICIENT_BUFFER = 122;

Span<DISPLAYCONFIG_PATH_INFO> paths = new Span<DISPLAYCONFIG_PATH_INFO>();
Span<DISPLAYCONFIG_MODE_INFO> modes = new Span<DISPLAYCONFIG_MODE_INFO>();
var flags = QUERY_DISPLAY_CONFIG_FLAGS.QDC_ONLY_ACTIVE_PATHS;
WIN32_ERROR result = 0;

do
{
    result = PInvoke.GetDisplayConfigBufferSizes(flags, out var pathCount, out var modeCount);

    if (result != WIN32_ERROR.ERROR_SUCCESS)
        return PInvoke.HRESULT_FROM_WIN32(result);

    paths = new Span<DISPLAYCONFIG_PATH_INFO>(new DISPLAYCONFIG_PATH_INFO[pathCount]);
    modes = new Span<DISPLAYCONFIG_MODE_INFO>(new DISPLAYCONFIG_MODE_INFO[modeCount]);

    result = PInvoke.QueryDisplayConfig(flags, ref pathCount, paths, ref modeCount, modes);
}
while (result == WIN32_ERROR.ERROR_INSUFFICIENT_BUFFER);

if (result != WIN32_ERROR.ERROR_SUCCESS)
    return PInvoke.HRESULT_FROM_WIN32(result);

foreach (var mode in modes)
{
    if (mode.infoType != DISPLAYCONFIG_MODE_INFO_TYPE.DISPLAYCONFIG_MODE_INFO_TYPE_TARGET)
        continue;

    DISPLAYCONFIG_TARGET_DEVICE_NAME targetName = new();
    targetName.header.adapterId = mode.adapterId;
    targetName.header.id = mode.id;
    targetName.header.type = DISPLAYCONFIG_DEVICE_INFO_TYPE.DISPLAYCONFIG_DEVICE_INFO_GET_TARGET_NAME;
    targetName.header.size = (uint)Marshal.SizeOf(targetName);

    result = (WIN32_ERROR)PInvoke.DisplayConfigGetDeviceInfo(ref targetName.header);

    if (result != WIN32_ERROR.ERROR_SUCCESS)
        return PInvoke.HRESULT_FROM_WIN32(result);

    Console.WriteLine($"Device Path: {targetName.monitorDevicePath}\n" +
                      $"Monitor FriendlyName: {targetName.monitorFriendlyDeviceName}\n" +
                      $"Connector Instance: {targetName.connectorInstance}\n" +
                      $"EDID ManufacturerID: {targetName.edidManufactureId}\n" +
                      $"EDID ProductId: {targetName.edidProductCodeId}\n");
}

Console.WriteLine("---------------------------");

foreach (var path in paths)
{
    DISPLAYCONFIG_TARGET_DEVICE_NAME targetName = new();
    targetName.header.adapterId = path.targetInfo.adapterId;
    targetName.header.id = path.targetInfo.id;
    targetName.header.type = DISPLAYCONFIG_DEVICE_INFO_TYPE.DISPLAYCONFIG_DEVICE_INFO_GET_TARGET_NAME;
    targetName.header.size = (uint)Marshal.SizeOf(targetName);

    result = (WIN32_ERROR)PInvoke.DisplayConfigGetDeviceInfo(ref targetName.header);

    if (result != WIN32_ERROR.ERROR_SUCCESS)
        return PInvoke.HRESULT_FROM_WIN32(result);

    DISPLAYCONFIG_ADAPTER_NAME adapterName = new();
    adapterName.header.adapterId = path.targetInfo.adapterId;
    adapterName.header.type = DISPLAYCONFIG_DEVICE_INFO_TYPE.DISPLAYCONFIG_DEVICE_INFO_GET_ADAPTER_NAME;
    adapterName.header.size = (uint)Marshal.SizeOf(adapterName);

    result = (WIN32_ERROR)PInvoke.DisplayConfigGetDeviceInfo(ref adapterName.header);

    if (result != WIN32_ERROR.ERROR_SUCCESS)
        return PInvoke.HRESULT_FROM_WIN32(result);

    Console.WriteLine($"Monitor Name: {targetName.monitorFriendlyDeviceName}\n" +
                      $"AdapterID: {adapterName.header.adapterId.HighPart}\n" +
                      $"DevicePath: {adapterName.adapterDevicePath}\n" +
                      $"Target: {path.targetInfo.id}");
}

return 0;

NativeMethods.txt

DISPLAYCONFIG_PATH_INFO
DISPLAYCONFIG_MODE_INFO
DEV_QUERY_FLAGS
GetDisplayConfigBufferSizes
QueryDisplayConfig
DisplayConfigGetDeviceInfo
QUERY_DISPLAY_CONFIG_FLAGS
HRESULT_FROM_WIN32
DISPLAYCONFIG_TARGET_DEVICE_NAME
DISPLAYCONFIG_ADAPTER_NAME