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 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 my experience with C and writing device
drivers is
extremely limited. 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 get DeviceId from within the WH_KEYBOARD_LL hook.
2. Finding a way to cancel keystrokes from within the Raw Input handler
(WndProc).
3. Alternative solution I have not explored...
Thanks,
-Steven
louiscypher@dod geit.com
(do not reply to this email, it is just for newsgroup postings)
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 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 my experience with C and writing device
drivers is
extremely limited. 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 get DeviceId from within the WH_KEYBOARD_LL hook.
2. Finding a way to cancel keystrokes from within the Raw Input handler
(WndProc).
3. Alternative solution I have not explored...
Thanks,
-Steven
louiscypher@dod geit.com
(do not reply to this email, it is just for newsgroup postings)
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