Questions about adding barcode scanning capability
in [Visual Basic]
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From: Henning on 17 May 2010 11:00 "Ron Weiner" <rweineratworksritedotcom> skrev i meddelandet news:%23h7e8GK9KHA.4316(a)TK2MSFTNGP04.phx.gbl... > > "Paulo" <nospam.pmpcosta(a)netcabo.pt> wrote in message > news:uF6%23e828KHA.2248(a)TK2MSFTNGP05.phx.gbl... >> Hi, friends >> >> I want to add barcode scanning capability to a next release of my >> application. A barcode with the identification of the customer will be >> printed in a form. After to fill in the form, customer sends back the >> report to my client. The operator of my application should be able to >> read the customer identification with a barcode scanner and, at this >> time, should be automaticaly loaded a dialog in order the operator to >> update data. >> >> Searching in the internet I found inWikipedia some useful code to draw >> the barcode, but couldn't find any good tutorial: >> >> http://www.google.com/search?hl=en&lr=&q=vb+vb6+barcode+scan+draw+tutorial+source+-net+-dot&btnG=Search&aq=f&aqi=&aql=&oq=&gs_rfai= >> >> I am completely new to this, and have some questions: >> >> a) Is it possible to implement this? >> b) Which type of barcode should be used in this type of application? >> c) Which type of barcode scanner to buy for tests? >> d) How to detect if a barcode scanner device is attached to the client >> computer? >> e) How to get a barcode value in a variable in my application? >> >> Thanks for any advice, >> >> Paulo >> ----- >> _I want my Classic VB_ >> >> > > > I have read all of the previous posted here and agree with most of > everything that the others have said. > > However using a barcode scanner as an alternative keyboard device or > keyboard wedge (IE where the scanner interpolates the barcode directly > into the keyboards data stream) is IMO a bad design. In this scenario the > user could use the scanner at ANY point in your program to interpolate a > string of characters from the barcode into your app that might do anything > depending on where your program was at the time. > > It would be a better design to use either a scanner that had a Serial or a > USB interface, and poll the device only when your app WANTED to process a > barcode. > > Rdub > > And what to do with old buffered "unwanted" scans while the app is not reading the input? /Henning
From: Ron Weiner on 17 May 2010 20:17 "David Kerber" <ns_dkerber(a)ns_warrenrogersassociates.com> wrote in message news:MPG.265b008a2b3f2d37989703(a)news.onecommunications.net... > In article <#h7e8GK9KHA.4316(a)TK2MSFTNGP04.phx.gbl>, "Ron Weiner" says... > > ... > >> However using a barcode scanner as an alternative keyboard device or >> keyboard wedge (IE where the scanner interpolates the barcode directly >> into >> the keyboards data stream) is IMO a bad design. In this scenario the >> user >> could use the scanner at ANY point in your program to interpolate a >> string >> of characters from the barcode into your app that might do anything >> depending on where your program was at the time. >> >> It would be a better design to use either a scanner that had a Serial or >> a >> USB interface, and poll the device only when your app WANTED to process a >> barcode. > > This is a point to consider, but IMO it really depends on what you know > about your users. My app is not commercially sold; it's strictly in- > house use, so I have tight control over my users' training, etc, and I > don't need to worry as much about idiot-proofing my app. Your situation > may be different, so plan accordingly. > > D If you have a level control over your apps users, Go For It! Just be aware of the potential unintended consequences. I am in a situation where the users have control over my app. It just has to work, my customers operate in a real time trade show floor environment, I have no time or money to handle support calls. Rdub
From: Ron Weiner on 17 May 2010 20:33 "Henning" <computer_hero(a)coldmail.com> wrote in message news:OEVVAHd9KHA.4768(a)TK2MSFTNGP04.phx.gbl... > > "Ron Weiner" <rweineratworksritedotcom> skrev i meddelandet > news:%23h7e8GK9KHA.4316(a)TK2MSFTNGP04.phx.gbl... >> >> "Paulo" <nospam.pmpcosta(a)netcabo.pt> wrote in message >> news:uF6%23e828KHA.2248(a)TK2MSFTNGP05.phx.gbl... >>> Hi, friends >>> >>> I want to add barcode scanning capability to a next release of my >>> application. A barcode with the identification of the customer will be >>> printed in a form. After to fill in the form, customer sends back the >>> report to my client. The operator of my application should be able to >>> read the customer identification with a barcode scanner and, at this >>> time, should be automaticaly loaded a dialog in order the operator to >>> update data. >>> >>> Searching in the internet I found inWikipedia some useful code to draw >>> the barcode, but couldn't find any good tutorial: >>> >>> http://www.google.com/search?hl=en&lr=&q=vb+vb6+barcode+scan+draw+tutorial+source+-net+-dot&btnG=Search&aq=f&aqi=&aql=&oq=&gs_rfai= >>> >>> I am completely new to this, and have some questions: >>> >>> a) Is it possible to implement this? >>> b) Which type of barcode should be used in this type of application? >>> c) Which type of barcode scanner to buy for tests? >>> d) How to detect if a barcode scanner device is attached to the client >>> computer? >>> e) How to get a barcode value in a variable in my application? >>> >>> Thanks for any advice, >>> >>> Paulo >>> ----- >>> _I want my Classic VB_ >>> >>> >> >> >> I have read all of the previous posted here and agree with most of >> everything that the others have said. >> >> However using a barcode scanner as an alternative keyboard device or >> keyboard wedge (IE where the scanner interpolates the barcode directly >> into the keyboards data stream) is IMO a bad design. In this scenario >> the user could use the scanner at ANY point in your program to >> interpolate a string of characters from the barcode into your app that >> might do anything depending on where your program was at the time. >> >> It would be a better design to use either a scanner that had a Serial or >> a USB interface, and poll the device only when your app WANTED to process >> a barcode. >> >> Rdub >> >> > > And what to do with old buffered "unwanted" scans while the app is not > reading the input? > > /Henning > > In my application I am reading scanned data right off of the USB bus. When the app wants the scanner to be active it polls the bus 5 time a second (it uses a timer control) looking for any data coming from my specific device. If the data is there the app handles it. When no data is there it returns till the next poll attempt. When the app is not looking for a scan, anything coming up from the device is ignored. The bits fall harmlessly into the great bit bucket in the sky. Rdub
From: mcnews on 20 May 2010 09:10 On May 14, 10:10 am, "Paulo" <nospam.pmpco...(a)netcabo.pt> wrote: > Hi, friends > > I want to add barcode scanning capability to a next release of my > application. A barcode with the identification of the customer will be > printed in a form. After to fill in the form, customer sends back the report > to my client. The operator of my application should be able to read the > customer identification with a barcode scanner and, at this time, should be > automaticaly loaded a dialog in order the operator to update data. > > Searching in the internet I found inWikipedia some useful code to draw the > barcode, but couldn't find any good tutorial: > > http://www.google.com/search?hl=en&lr=&q=vb+vb6+barcode+scan+draw+tut... > > I am completely new to this, and have some questions: > > a) Is it possible to implement this? > b) Which type of barcode should be used in this type of application? > c) Which type of barcode scanner to buy for tests? > d) How to detect if a barcode scanner device is attached to the client > computer? > e) How to get a barcode value in a variable in my application? > > Thanks for any advice, > > Paulo > ----- > _I want my Classic VB_ it's pretty simple really. buy a scanner and plug it in, download a 39 font, put a textbox on your form, write some code to deal with the input, run your app, put the cursor in the textbox, scan your barcode - bingo. don't use a keyboard wedge. when they become disabled (which they often do) you have to reboot. i've used USB hand-helds that cost $50 or so that work fine. i've also used remote scanners that dump multiple scanned codes via a USB receiver.
From: Henning on 20 May 2010 09:45
"mcnews" <mcourter(a)mindspring.com> skrev i meddelandet news:e4bece33-29cd-47ac-9775-dc83ccee791f(a)e21g2000vbl.googlegroups.com... On May 14, 10:10 am, "Paulo" <nospam.pmpco...(a)netcabo.pt> wrote: > Hi, friends > > I want to add barcode scanning capability to a next release of my > application. A barcode with the identification of the customer will be > printed in a form. After to fill in the form, customer sends back the > report > to my client. The operator of my application should be able to read the > customer identification with a barcode scanner and, at this time, should > be > automaticaly loaded a dialog in order the operator to update data. > > Searching in the internet I found inWikipedia some useful code to draw the > barcode, but couldn't find any good tutorial: > > http://www.google.com/search?hl=en&lr=&q=vb+vb6+barcode+scan+draw+tut... > > I am completely new to this, and have some questions: > > a) Is it possible to implement this? > b) Which type of barcode should be used in this type of application? > c) Which type of barcode scanner to buy for tests? > d) How to detect if a barcode scanner device is attached to the client > computer? > e) How to get a barcode value in a variable in my application? > > Thanks for any advice, > > Paulo > ----- > _I want my Classic VB_ it's pretty simple really. buy a scanner and plug it in, download a 39 font, put a textbox on your form, write some code to deal with the input, run your app, put the cursor in the textbox, scan your barcode - bingo. don't use a keyboard wedge. when they become disabled (which they often do) you have to reboot. i've used USB hand-helds that cost $50 or so that work fine. i've also used remote scanners that dump multiple scanned codes via a USB receiver. I have used wireless barcode scanners as keyboard wedge for over 10 years, without *any* problems. With up to 4 scanners per app, using a prefix (DC1,DC2,DC3,DC4) and a suffix (CR), catching what is keyboard or scanner input has never failed. Secondly, I don't even need the scanner for testing. Just key-in Ctrl-Q, the code, Ctrl-M, to fake a reader input. /Henning |