Updated December 24, 1999 ![]() For more detailed information about barcode technology, see Barcode1. This updated sample application, now provided as source-code only, illustrates almost every capability of the HTML Help class module. It's similar in operation to my original Case Study 2, "A Library Transaction Wizard", from Peter Wright's Beginning Visual Basic 6 (Wrox Press 1998, ISBN 1-861001-05-3). The difference is that, in this version, almost every conceivable HTML Help call is demonstrated. The sample code also works under Visual Basic 6. If the source code is opened and run in Visual Basic 6, or compiled with it, What's This Help on the Check-Out form will work just fine. This is so you can see an example of how this works. However, once you do this, if the project is saved, it won't open again in Visual Basic 5 without a small fix. You need to open the VBP file in NotePad and remove the line "RETAINED=0" before it will open in Visual Basic 5 again. The check-out process is based on the same process libraries have been using for a very long time. The process works like this:
The check-in procedure is quite simple:
Note that a barcode scanner is not required for you to use this sample application. The sample was designed for use with the type of scanner called a keyboard wedge. This is a small handheld scanner which connects to the computer via a 'Y' connector which ties in to the keyboard connection. Both the keyboard and scanner are connected at the same time. This type of scanner sends the barcode information to the computer in the form of keyboard data, and can be programmed to send a simulated Enter keypress at the end of the barcode. The data pops into whichever control has the focus, the Enter keypress clicks the default button, and the process continues almost instantaneously at the next step. The keyboard can also be used to enter data from damaged or unreadable barcodes. Here, we'll use the keyboard to enter data since you likely don't have a keyboard wedge scanner. |
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