[Lazarus] Fw: Re: One last ask for help

"ArĂ­ Ricardo Ody" aro52 at gmx.com
Thu Mar 21 15:02:43 CET 2013


----- Original Message -----
From: Antonio Fortuny
Sent: 03/21/13 09:37 AM
To: lazarus at lists.lazarus.freepascal.org
Subject: Re: [Lazarus] Fw: Re: One last ask for help

Hi Ricardo. ---> Hi Antonio As of my last experience (Datalogic, Motorola former Symbol models, all using WinCE) the scanner itself needs to be very carefully configured. --->Can tell little bit more about this? AKAIK in all models I've tested, the barcode scanner sends the chars as if they were typed on the keyboard. Because of this it is difficult to distinguish the source: the scanner or the keyboard. ---> In my application it doesn't matter That's why I have setup the scanner to send a prefix and a suffix whith the barcode itself. I use the STX and ETX special characters. In my applications the barcode itself is gathered silently because it has no meaning for the user but it is sometimes displayed in a TLabel. ---> In my application user must see the code scanned. Are you suggesting that I can't see the code because I wait the input in a TEdit? If I use a TLabel it will be showed? Anyway, in all cases I use the KeyPreview event of the form. ---> What is the exactly use of this event in this case? I open a nem porject in Lazarus 1.0 RC1(Is the only one I have in this machine in my work) and can't find the KeyPreview event. I crate a project and put a TEdit in it. And can't find the KeyPreview? Excuse me for weak knowledge. If I get the STX all next characters are stored in a barcode string until the EOT is catched otherwise they follow the standard process and are caught by the focused control. This way I can mix, in the application, input coming from the KB (quantities, weights, etc.) and from the scanner. To have the characters sent by the scanner into an edit field, the edit field must have the focus otherwise either the characters are lost (no input fields capable of input) or they go into a misfocused control. Do not forget (see scanner config) that usually the scanner sends a CR+LF (or only LF) after the last character of the scanning process. So focus may change too. ---> I use the barcode reader with the focus in a TEdit. I'm sure of this. I've tested with a little porject with a FOrm and only a TEdit that remains waiting input. Again nothing was read. I beleive that it isn't case of CR+LF or only LF 'cause teh focus doesn't change aftger the barcode read. Which is your opinion about the fact of scanner lost the first character scanned? It occurs in another handheld model. Would it be a kind of clue about the cause of the problem at all? Thanks Antonio. -- _______________________________________________ Lazarus mailing list Lazarus at lists.lazarus.freepascal.org http://lists.lazarus.freepascal.org/mailman/listinfo/lazarus
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