internal static extern bool RegisterRawInputDevices(RAWINPUTDEVICE[] pRawInputDevice, uint numberDevices, uint size);
public bool RegisterRawInput(IntPtr hwnd)
{
var rid = new RAWINPUTDEVICE[1];
rid[0].UsagePage = HidUsagePage.GENERIC;
rid[0].Usage = HidUsage.Keyboard;
rid[0].Flags = RawInputDeviceFlags.INPUTSINK;
rid[0].Target = hwnd;
return (NativeMethods.RegisterRawInputDevices(rid, (uint)rid.Length, (uint)Marshal.SizeOf(rid[0])));
}