Distinguish mice devices from a LowLevel mouse hook

Question

I have a virtual mouse driver and an actual mouse on my computer.

I'm using LowLevelMouseProc to capture events windows wide and I would like to not process events from the virtual mouse.

I cannot use RawInput as I need to process message of another process.

Is there any way to know which device has sent the message ?

Forcing the dwExtraInfo also on a real mouse device may help me if possible.

private IntPtr HookCallback(int nCode, IntPtr wParam, IntPtr lParam)
{
    MSLLHOOKSTRUCT hookStruct;
    if (nCode < 0)
    {
        return CallNextHookEx(_hookId, nCode, wParam, lParam);
    }
 
    hookStruct = (MSLLHOOKSTRUCT) Marshal.PtrToStructure(lParam, typeof(MSLLHOOKSTRUCT));

    // I'd like to know from here which mouse has sent the message. 
    return CallNextHookEx(_hookId, nCode, wParam, lParam);
}

score 1 · Answer 1 · edited Jun 06 '21 at 08:29

There is nothing exposed from the .NET Windows API to distinguish between different mice. There was a Microsoft SDK for multiple inputs at one time but it was dropped before Windows 10 so it likely doesn't work anymore.

rawinput-sharp shows how to do it but it uses raw input, as the name suggests, which I know you said you don't want to do. This limitation you have put on yourself has gotten you stuck. It's like saying "how do I see the screen with my eyes closed?"

Perhaps you could correlate the two events somehow to get the filter you are looking for. Or maybe you could filter out all events from the LowLevelMouseProc and pass the raw input from just one device into the LowLevelMouseProc.

There is a related discussion from the GameDev SE site.

Distinguish mice devices from a LowLevel mouse hook

1 Answers1