Why is it that people think they can start a Comp Sci course, get online, and post messages like this:
I need caculatore source
I need help for this program i dont know how do this program...
Of course, once they 'graduate', or, more likely, when they get given a job because they know how to turn a computer on, they do the same thing:
read barcode using usb scanner
hello....
i am working on a project(c#).. i need a module to read bar code (EAN-13).
plz help me ... it,s urgent...
Every day, I see people posting and basically saying 'I was asked to do this, please give me the code, it's urgent'. And yet, some of these people get told how to do the task, and over the next few weeks will just ask the same question over and over again, without any reference to prior solutions. That's because these are people who cannot program, who cannot understand what programmers are saying when they explain how to do a task, and basically are sitting there sweating a deadline, hoping that some random person on the internet is going to send them a complete solution, so they can get paid.
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Hah I just had to do EAN-13 barcode aswell :)
ReplyDeleteI can definatly say even without knowing anything about it (well a little bit about it) it only takes about 1 day to find all the information and code you need (k you have to alter the code a little bit but if you know what your doing that's not hard) to do this.
A little bit of research goes a long way and you'll likely to remember the solution a lot longer than when your just handed the code.
Keep up the good work CG. :)
Most USB-scanners act as a keyboard HID-device, delivering the barcode as if it was typed in. If they then proceed to read the manual, they'll find out that they can program it to send prefixes and suffixes, that can easily be intercepted by the application. That's the fast and easy way...
ReplyDeleteA bit more complicated is to program the scanner to emulate a serial scanner - the driver must then setup a virtual COM port. Then it's just a matter of reading from the COM port.
An even more advanced method is to just hook into the HID device with a filter driver, and deliver the barcode to your own app with your own methods.
Any newbie should be able to perform the first of the mentioned methods.