Add a KeyDown handler to the textbox and verify whether it receives same key codes with and without the keyboard present? If the key codes are the same but the printed characters differ, probably the card reader software expects the app to run under a specific keyboard layout (what Windows uses to map virtual key codes to actual characters), and the keyboard initialization code changes it to a different one.

If your keyboard initialization code includes assignment to InputLocale, try removing it. The keyboard itself shouldn't change the keyboard layout automatically, but just in case try moving the card reader initialization code after the keyboard's one - could help if both the reader and the keyboard activate a keyboard layout.

Also if you aren't on v4.4.2, try upgrading to it. Latest version disables a feature where current thread's UI culture was automatically set to match input locale, which might lead to changing textbox' font or character encoding. If you are already on v4.4.2, make sure you haven't set AutoUpdateCulture to true.

Regards,
Slavcho
Mindfusion

Quote:


Do you mean the text box gets different key code values from card reader when you add keyboard to your application? Or the key codes are the same but the characters are bad?

Do the characters look like showing the shift-variant of characters, say !@#$ instead of 1234 (US keyboard layout)?

Regards,
Slavcho

While the reader is sending data, does it show VirtualKeyboard.KeyPressed event firing if you call Debug.Write from its handler?

Hi Mike,

What key codes does it log with and without the keyboard ?

textbox.KeyDown += (s, e) => Debug.WriteLine("down: " + e.KeyValue + " mod:" + e.Modifiers);
textbox.KeyUp += (s, e) => Debug.WriteLine("up: " + e.KeyValue + " mod:" + e.Modifiers);
 

Is the form created in response to some card reader event indicating it will start sending data? The keyboard initialization code sets modifier key states a few times and resets them afterwards. If the reader sends key events just then, that could change key code to character mapping. You should be able to work around it by creating the form earlier and just setting it visible when needed.

I've browsed Magtek documentation - keyboard emulation is listed as legacy compatibility mode there, and recommends using a dedicated card reader API that will read directly through USB interface. Not sure if this applies to model you are using.

Regards,
Slavcho

Hi,

I guess there might be some difference showing from the version of the operating system or .NET framework running on Atom processors. What's the MSR device' exact model?

Here's something similar happening -
https://serverfault.com/questions/64594/magnetic-stripe-reader-over-terminal-ser
ver-has-random-uppercase-lowercase-nonse

Is your application running directly on the tablet, or it shows through remote connection too by chance? Does it make any difference whether you type on the keyboard before using the reader?

You could also check if you can't read the data directly through .NET POS APIs as in https://code.msdn.microsoft.com/windowsapps/Magnetic-stripe-reader-30aa2ca5

Regards,
Slavcho