[RESOLVED] RegisterRawInputDevices fails with no error

[Sk#]

Hi everyone,

I want to use the RawInput API in my program to handle HIDs. However, I can't even register any device, as RegisterRawInputDevices fails (returns FALSE). When I call GetLastError(), I get 0, which means no error.

Here's my code, which is a minimal variation of the example taken from the MSDN:

#include <windows.h>

int main(int argc, char** argv)
{
	RAWINPUTDEVICE Rid[2];
	    
	Rid[0].usUsagePage = 0x01; 
	Rid[0].usUsage = 0x02; 
	Rid[0].dwFlags = RIDEV_NOLEGACY;   // adds HID mouse and also ignores legacy mouse messages
	Rid[0].hwndTarget = 0;

	Rid[1].usUsagePage = 0x01; 
	Rid[1].usUsage = 0x06; 
	Rid[1].dwFlags = RIDEV_NOLEGACY;   // adds HID keyboard and also ignores legacy keyboard messages
	Rid[1].hwndTarget = 0;

	if (RegisterRawInputDevices(Rid, 2, sizeof(Rid[0])) == FALSE) 
	{
		DWORD err = GetLastError();
	}

	return 0;
}

I've tried similar code (I don't have it here, so I can't make an accurate line-to-line comparison) on another machine, and there it worked. On my laptop, it worked for a while, then it stopped working.

I suspect this has something to do with my specific setup; in particular, in (apparently) unrelated news, I installed and configured (and re-configured) software such as PPJoy in order to use a Wiimote as a HID. However, my software didn't work before installing PPJoy, started working after some tentative configurations of PPJoy, then stopped working again.

I will perform tests on other machines, to check if my experiments broke something, but before that I would like to know if some of you have had a similar experience. I find it especially weird that RegisterRawInputDevices fails without marking any error...