I'm working on an application (OEM) using c# that uses input from a keyboard
and a USB Barcode Scanner.
I need to be able to identify keystrokes from the barcode scanner and remove
them from the message queue, regardless of what application has focus.
I can identify the keystrokes and input device by registering for raw input
(RegisterRawInp utDevices) and processing the WM_INPUT message. This gives
me the keystrokes and the ability to identify the USB Scanner. I have
looked into DirectInput, but it is my understanding that it uses WM_INPUT
underneath, and gives me no more information or ability than I currently
have.
I can cancel keystrokes using WH_KEYBOARD_LL and returning "-1" from my
callback.
*** Here's The Issue ***
However, the keyboard hook (WH_KEYBOARD_LL ) is processed BEFORE the raw
input (WM_INPUT). When I cancel the keystrokes in the hook, the raw input
never appears.
I'm at a loss on how to resolve this situation. I do not want to write a
device driver (keyboard filter) for the barcode scanner as the scanner is
3rd party, and I do not have control over what scanners will be used. I
feel like I'm 90% there, and there must be something simple I'm missing.
Does anybody have any ideas on:
1. Finding a way to GetRawInputData from within the WH_KEYBOARD_LL hook.
2. Finding a way to cancel keystrokes from within the Raw Input handler.
3. Alternative solution I have not explored...
Thanks,
-Steven
lo*********@dod geit.com
(do not reply to this email, it is just for newsgroup postings)
