1. What is a barcode?
Baidu Encyclopedia definition: bar code (barcode) is the width of a number of black bars and blank, according to a certain coding rules, to express a set of information graphic identifier. A common barcode is a pattern of parallel lines of black strips (short strips) and white bars (short ones) that vary greatly in reflectivity. In daily life, bar code can be marked out of the goods producing countries, manufacturers, product names, production dates, book classification number, mail location, the type, date and many other information. Please refer to the Barcode encoding format for details
Printed coupons, merchants need to use the authenticator to read the barcode, to obtain its validity.
2. How do I generate barcodes?
First find strong open source materials, download the Barcodegen.1d-php5.v5.0.1.zip version on barcode website, and then extract the files to the root directory of your Apache server
2.2 Specific analysis
(1) Class folders are classes that have been packaged to generate barcodes, and only need to be called.
(2) index.php is an optional condition to generate barcode function, is the main program entrance, and the HTML folder is provided by the referenced code, code39.php refers to the default encoding format.
(3) test.php is another example of generating a hello barcode directly from the code.
Setscale (2); $code->setthickness (30); The thickness of the barcode $code->setforegroundcolor ($color _black); Barcode Color $code->setbackgroundcolor ($color _white); Blank gap color $code->setfont ($font); $code->parse (' HELLO '); The data content required by the barcode} catch (Exception $exception) {$drawException = $exception;} Draw the barcode according to the above conditions $drawing = new Bcgdrawing (", $color _white); if ($drawException) {$drawing->drawexception ($ drawexception);} else {$drawing->setbarcode ($code); $drawing->draw ();} Generate a PNG-formatted picture header (' content-type:image/png '); $drawing->finish (bcgdrawing::img_format_png);? >
3. Practical Application
For a general understanding of the above, we can re-integrate the code below, more convenient to use it.
First create a new buildcode.php file, overwrite it according to the test.php file, and fetch the data from the requested file:
1). Barcode encoding Format
2). The data content required by the barcode
Setscale (2); Resolution $code->setthickness (23); Thickness $code->setforegroundcolor ($color _black); Color of Bars $code->setbackgroundcolor ($color _white); Color of Spaces $code->setfont ($font); Font (or 0) $text = $_request[' text ']; The barcode will $code->parse ($text) The contents of the data;} catch (Exception $exception) {$drawException = $exception;}/* Here is the list of the Arguments-filename (empty:disp Lay on screen)-Background color */$drawing = new Bcgdrawing (", $color _white), if ($drawException) {$drawing->drawexc Eption ($drawException);} else {$drawing->setbarcode ($code); $drawing->draw ();} Header that says it's an image (remove it if you save the barcode to a file) header (' content-type:image/png '); Draw (or save) the image into PNG format. $drawing->finish (bcgdrawing::img_format_png);? >
Then create a new test.html file and request data to buildcode.php
Test with embedded image
Last access, the browser generates a PNG-formatted barcode directly
where Codebar supports encoding formats that can be requested by the user:
/* ' Bcgcodabar ', ' BCGcode11 ', ' BCGcode39 ', ' bcgcode39extended ', ' BCGcode93 ',
' BCGcode128 ', ' BCGean8 ', ' BCGean13 ', ' bcgisbn ', ' BCGi25 ', ' BCGs25 ', ' Bcgmsi ',
' BCGUPCA ', ' bcgupce ', ' BCGupcext2 ', ' BCGupcext5 ', ' bcgpostnet ', ' bcgothercode ' * *
All that's left is to verify
4. Verification
How do we verify that the barcode is valid, that is, the ability to read the contents of the barcode.
First save the picture, and then visit the official website to provide the verification function, upload the image is ok!