I thought I'd ask you before I search the net!

How can I determine which USB keypad has caused a key event in my VB app.

My app records scores in a competition and each judge has a keypad. I need to know the key value (OK, I get that as a keyValue argument) but I also need to know whether a particular judge has given his score yet.

Alternatively, can I take control of the keypads somehow?

Thanks Rod

Phil

Sorry but I have no clue on that one. If you can't make the devices identify themselves in some way, it may be tough.

Rod

Rod Stephens, Visual Basic MVP
RodStephens@vb-helper.com

*** New Book ***
"Visual Basic 2008 Programmer's Reference"

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Well, I've found I need to use Raw Input which is in the User32 dll.
Unfortunately, all the samples are in C or C++. It uses structures like

        [StructLayout(LayoutKind.Sequential)]
        internal struct RAWINPUTDEVICE
        {
            [MarshalAs(UnmanagedType.U2)]
            public ushort usUsagePage;
            [MarshalAs(UnmanagedType.U2)]
            public ushort usUsage;
            [MarshalAs(UnmanagedType.U4)]
            public int dwFlags;
            public IntPtr hwndTarget;
        }

and API calls like


        [DllImport("User32.dll")]
        extern static bool RegisterRawInputDevices(RAWINPUTDEVICE[] pRawInputDevice, uint uiNumDevices, uint cbSize);



In VB6 I'd have got a reference via
Declare function RegisterRawInputDevices lib "USER32" (pRawInpoutDevice as ptr, numDevices as Integer, size as Integer) as boolean

but is there a better way in VB.net and how do I best create the structure and its pointer?

I've got RawInput working nicely, but it returns a RawInput code that only tells me which key was pressed. I doesn't tell me the ASCII code for the key. I can manage the shift, alt and ctl keys OK, but the ASCII meaning of a key is dependent on the keyboard in use. For example, if I shift-press the 4th key on the top row of my English keyboard I get the UK currency symbol £. If you press the same key on a US keyboard it generates the same code but means # (or possibly cent - I forget which)

Somewhere in Windows there is a table that converts RawInput codes to ASCII - any idea where?

(PS I'm going to cross-post this on a Windows site)

Cheers

Phil