Having trouble with retrieving device path using SetUpApi and Hidsdi

Question

I'm currently having an issue with my code that detects HID devices with a specific VID and PID for joy-cons. I'm using SetUpApi and Hidsdi that I platform invoked, but the device path is only showing as question marks. Can someone assist in finding a solution? Here's the code I'm working with.

using System;

using System.Runtime.InteropServices;

class Program

{

[DllImport("hid.dll")]

private static extern void HidD_GetHidGuid(out Guid HidGuid);

[DllImport("setupapi.dll")]

private static extern IntPtr SetupDiGetClassDevs(ref Guid ClassGuid, string Enumerator, IntPtr hwndParent, uint Flags);

[DllImport("setupapi.dll")]

private static extern bool SetupDiEnumDeviceInterfaces(IntPtr DeviceInfoSet, IntPtr DeviceInfoData, ref Guid InterfaceClassGuid, uint MemberIndex, ref SP_DEVICE_INTERFACE_DATA DeviceInterfaceData);

[DllImport("setupapi.dll")]

private static extern bool SetupDiGetDeviceInterfaceDetail(IntPtr DeviceInfoSet, ref SP_DEVICE_INTERFACE_DATA DeviceInterfaceData, IntPtr DeviceInterfaceDetailData, uint DeviceInterfaceDetailDataSize, out uint RequiredSize, IntPtr DeviceInfoData);

[DllImport("setupapi.dll")]

private static extern void SetupDiDestroyDeviceInfoList(IntPtr DeviceInfoSet);

[StructLayout(LayoutKind.Sequential)]

private struct SP_DEVICE_INTERFACE_DATA

{

public uint cbSize;

public Guid InterfaceClassGuid;

public uint Flags;

public IntPtr Reserved;

}

[StructLayout(LayoutKind.Sequential, CharSet = CharSet.Auto)]

private struct SP_DEVICE_INTERFACE_DETAIL_DATA

{

public uint cbSize;

[MarshalAs(UnmanagedType.ByValTStr, SizeConst = 256)]

public string DevicePath;

}

[StructLayout(LayoutKind.Sequential)]

private struct SP_DEVINFO_DATA

{

public uint cbSize;

public Guid ClassGuid;

public uint DevInst;

public IntPtr Reserved;

}

private const uint DIGCF_PRESENT = 0x00000002;

private const uint DIGCF_DEVICEINTERFACE = 0x00000010;

static void Main()

{

Console.WriteLine("Retrieving HID GUID...");

Guid hidGuid;

HidD_GetHidGuid(out hidGuid);

Console.WriteLine($"HID GUID: {hidGuid}");

Console.WriteLine("Getting device info set...");

IntPtr deviceInfoSet = SetupDiGetClassDevs(ref hidGuid, null, IntPtr.Zero, DIGCF_PRESENT | DIGCF_DEVICEINTERFACE);

if (deviceInfoSet == (IntPtr)(-1))

{

Console.Error.WriteLine("Error getting device info set");

return;

}

Console.WriteLine("Device info set retrieved successfully.");

SP_DEVICE_INTERFACE_DATA deviceInterfaceData = new SP_DEVICE_INTERFACE_DATA();

deviceInterfaceData.cbSize = (uint)Marshal.SizeOf(deviceInterfaceData);

Console.WriteLine("Initialized SP_DEVICE_INTERFACE_DATA.");

uint index = 0;

while (SetupDiEnumDeviceInterfaces(deviceInfoSet, IntPtr.Zero, ref hidGuid, index++, ref deviceInterfaceData))

{

Console.WriteLine($"Enumerating device interface #{index + 1}...");

uint requiredSize = 0;

SetupDiGetDeviceInterfaceDetail(deviceInfoSet, ref deviceInterfaceData, IntPtr.Zero, 0, out requiredSize, IntPtr.Zero);

if (requiredSize == 0)

{

Console.Error.WriteLine("Error getting required size for device interface detail");

continue;

}

Console.WriteLine($"Required size for device interface detail: {requiredSize}");

IntPtr detailDataBuffer = IntPtr.Zero;

try

{

detailDataBuffer = Marshal.AllocHGlobal((int)requiredSize);

Marshal.WriteInt32(detailDataBuffer, (int)(IntPtr.Size == 8 ? 8 : 5)); // cbSize for 64-bit or 32-bit

Console.WriteLine("Allocated memory for SP_DEVICE_INTERFACE_DETAIL_DATA.");

if (SetupDiGetDeviceInterfaceDetail(deviceInfoSet, ref deviceInterfaceData, detailDataBuffer, requiredSize, out requiredSize, IntPtr.Zero))

{

IntPtr pDevicePath = IntPtr.Add(detailDataBuffer, 4); // Offset for cbSize (4 bytes)

string devicePath = Marshal.PtrToStringAuto(pDevicePath);

Console.WriteLine($"Device path: {devicePath}");

string searchString = "pid&2007";

string otherSearchString = "pid&2006";

string VIDstring = "vid&0002057e";

if (devicePath != null && (devicePath.Contains(searchString) || devicePath.Contains(otherSearchString)))

{

if (devicePath.Contains(VIDstring))

{

Console.WriteLine("Yep, It's a joycon!");

}

}

}

else

{

Console.Error.WriteLine("Error getting device interface detail");

}

}

finally

{

if (detailDataBuffer != IntPtr.Zero)

{

Marshal.FreeHGlobal(detailDataBuffer);

Console.WriteLine("Freed allocated memory for SP_DEVICE_INTERFACE_DETAIL_DATA.");

}

}

}

SetupDiDestroyDeviceInfoList(deviceInfoSet);

Console.WriteLine("Destroyed device info set.");

}

}

(Srry if i'm not supposed to post all of this code, this is my first post.)

Answer 1

I get correct Device path with this test :

{
    string sDevicePath = null;
    Guid hidGuid;
    HidD_GetHidGuid(out hidGuid);
    IntPtr hDeviceInfoSet = SetupDiGetClassDevs(ref hidGuid, IntPtr.Zero, IntPtr.Zero, DIGCF_DEVICEINTERFACE | DIGCF_PRESENT);
    if (hDeviceInfoSet != IntPtr.Zero)
    {
        var did = new SP_DEVICE_INTERFACE_DATA() { cbSize = Marshal.SizeOf(typeof(SP_DEVICE_INTERFACE_DATA)) };
        for (var nIndex = 0; SetupDiEnumDeviceInterfaces(hDeviceInfoSet, IntPtr.Zero, ref hidGuid, nIndex, ref did); nIndex++)
        {
            int dwBytes = 0;
            bool bRet = SetupDiGetDeviceInterfaceDetail(hDeviceInfoSet, ref did, IntPtr.Zero, 0, ref dwBytes, IntPtr.Zero);
            if (!bRet && Marshal.GetLastWin32Error() == ERROR_INSUFFICIENT_BUFFER)
            {
                SP_DEVICE_INTERFACE_DETAIL_DATA didd = new SP_DEVICE_INTERFACE_DETAIL_DATA();
                didd.cbSize = IntPtr.Size == 8 ? 8 : 6;                
                SP_DEVINFO_DATA dd = new SP_DEVINFO_DATA();
                dd.cbSize = Marshal.SizeOf(dd);
                bRet = SetupDiGetDeviceInterfaceDetail(hDeviceInfoSet, ref did, ref didd, dwBytes, ref dwBytes, ref dd);
                if (bRet)
                {
                    sDevicePath = didd.DevicePath;
                    Console.WriteLine("Device Path : {0}", sDevicePath);
                }
            }
        }
        SetupDiDestroyDeviceInfoList(hDeviceInfoSet);
    }
}

with :

        [DllImport("Hid.dll", CharSet = CharSet.Unicode, SetLastError = true)]
        public static extern void HidD_GetHidGuid(out Guid HidGuid);
        
        [DllImport("Setupapi.dll", CharSet = CharSet.Unicode, SetLastError = true)]
        public static extern IntPtr SetupDiGetClassDevs(ref Guid ClassGuid, IntPtr Enumerator, IntPtr hWndParent, int Flags);
        
        public const int DIGCF_PRESENT = 0x00000002;
        public const int DIGCF_DEVICEINTERFACE = 0x00000010;
        public const int ERROR_INSUFFICIENT_BUFFER = 122;
        public const int MAX_PATH = 260;

        [StructLayout(LayoutKind.Sequential, CharSet = CharSet.Unicode, Pack = PACK_SIZE)]
        public struct SP_DEVINFO_DATA
        {
            public int cbSize;
            public Guid ClassGuid;
            public int DevInst;
            public IntPtr Reserved;
        }
#if WIN64
        public const int PACK_SIZE = 8;
#else
        public const int PACK_SIZE = 1;
#endif

        [DllImport("Setupapi.dll", CharSet = CharSet.Unicode, SetLastError = true)]
        public static extern bool SetupDiGetDeviceInterfaceDetail(IntPtr DeviceInfoSet, ref SP_DEVICE_INTERFACE_DATA DeviceInterfaceData, ref SP_DEVICE_INTERFACE_DETAIL_DATA DeviceInterfaceDetailData, int DeviceInterfaceDetailDataSize, ref int RequiredSize, ref SP_DEVINFO_DATA DeviceInfoData );

        [DllImport("Setupapi.dll", CharSet = CharSet.Unicode, SetLastError = true)]
        public static extern bool SetupDiGetDeviceInterfaceDetail(IntPtr DeviceInfoSet, ref SP_DEVICE_INTERFACE_DATA DeviceInterfaceData, IntPtr Ptr, int DeviceInterfaceDetailDataSize, ref int RequiredSize, IntPtr PtrInfo);

        [DllImport("Setupapi.dll", CharSet = CharSet.Unicode, SetLastError = true)]
        public static extern bool SetupDiEnumDeviceInterfaces(IntPtr DeviceInfoSet, IntPtr DeviceInfoData, ref Guid InterfaceClassGuid, int MemberIndex, ref SP_DEVICE_INTERFACE_DATA DeviceInterfaceData);

        [StructLayout(LayoutKind.Sequential)]
        public struct SP_DEVICE_INTERFACE_DATA
        {
            public int cbSize;
            public Guid InterfaceClassGuid;
            public int Flags;
            public IntPtr Reserved;
        }

        [StructLayout(LayoutKind.Sequential, CharSet = CharSet.Unicode)]
        public struct SP_DEVICE_INTERFACE_DETAIL_DATA
        {
            public int cbSize;
            [MarshalAs(UnmanagedType.ByValTStr, SizeConst = MAX_PATH)]
            public string DevicePath;
        }  
        
        [DllImport("Setupapi.dll", CharSet = CharSet.Unicode, ExactSpelling = true, SetLastError = true)]
      	public static extern bool SetupDiDestroyDeviceInfoList(IntPtr DeviceInfoSet);