Generate QR code with PHP_PHP tutorial-PHP Tutorial-php.cn

Parameter description:

cht=qr: necessary parameter, fixed value , indicating that a QR code is to be generated

chs=x: Necessary parameters, generated QR code size, the unit is pixels, the currently generated QR codes are all square, so both width and height values are set to the same value

chl=: Necessary parameter to generate the information contained in the QR code, which can be numbers, characters, binary information, and Chinese characters. Data types cannot be mixed, and the data must be UTF-8 URL-encoded. If the information that needs to be transferred exceeds 2K bytes, the POST method needs to be used

choe=: Optional parameter, encoding format. Including three options: UTF-8/Shift_JIS/ISO-8859-1, the default is UTF-8.

chld=|: optional parameter,

Error_correction_level: Error tolerance level (divided into four levels, L-default: can identify 7% of the data that has been lost; M-can identify 15% of the data that has been lost; Q-can identify 25% of the data that has been lost; H-Can identify data that has lost 30%)

Margin: the distance between the generated QR code and the image border

Example 1: Scan the QR code to open the URL (API)

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//QR code information, encoded with urlencode

$data = urlencode('http://www.baidu.com');

//Generate QR code size

$size = '300x300';

//Complete API address

$qrurl = "http://chart.googleapis.com/chart?chs=$size&cht=qr&chl=$data&chld=L|1&choe=UTF-8";

//Get the QR code

$qrcode = file_get_contents($qrurl);

//Output picture

header('Content-type: image/png');

echo $qrcode;

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After opening a website, we need to realize the purpose of returning to the original. Scan the QR code and import the company information into the address book, that is, include a business card information in the QR code. In fact, the QR code is to put a business card into the address book. It converts piles of information into the form of pictures, and it doesn't care what this pile of information looks like. What really cares about this information is the tool for scanning QR codes. Taking the above example, when you use WeChat to scan QR codes, After QR code, WeChat reads the data stored in the QR code, and then tries to identify it. When it finds that the content is a Baidu URL, it uses a browser to open it. Similarly, when it finds that the content is a bunch of simple text data When it is displayed in the form of text, WeChat can also identify whether the content of the QR code is an electronic business card in vcard format. Most of our mobile phone address books are imported and exported in this format, so we can directly The QR code contains a standard vcard electronic business card, which allows the scanning tool to recognize it as an address book.

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The vcard format reference is as follows:

BEGIN:VCARD

VERSION:3.0

FN: Username

TEL;CELL;VOICE:18858140621

TEL;WORK;VOICE:0358-2157466

TEL;WORK;FAX:0358-2157466

EMAIL;PREF;INTERNET:lzw#lzw.me

URL:http://lzw.me

orG:Zhiwen Studio

ROLE:Product Department

TITLE:CTO

ADR;WORK;POSTAL: No. 35, North Fourth Ring Middle Road, Chaoyang District, Beijing; 100101

REV:2012-12-27T08:30:02Z

END:VCARD

If you want to customize the required format in more detail, please Baidu vcard format standard.

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Example 2: Generate a business card QR code (API)

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//Construct a vcard format data

$vcard =

"BEGIN:VCARD".

"nVERSION:3.0".

"nFN: Xiaobian Luoluo".

"nTEL;CELL;VOICE:18858140621".

"nTEL;WORK;VOICE:0358－2157466".

"nEMAIL:luoluo@qq.com".

"nURL:http://www.baidu.com".

"nADR: Binjiang District, Hangzhou City, Zhejiang Province".

"nEND:VCARD";

//QR code information, encoded with urlencode

$data = urlencode($vcard);

//Generate QR code size

$size = '300x300';

//Complete API address

$qrurl = "http://chart.googleapis.com/chart?chs=$size&cht=qr&chl=$data&chld=L|1&choe=UTF-8";

//Get the QR code

$qrcode = file_get_contents($qrurl);

//Output picture

header('Content-type: image/png');

echo $qrcode;

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So far, our goal of returning to the original has been basically achieved, but in actual use, because the above assembled url was directly added to the src attribute of the img tag, there was a slight problem, because our business card information is relatively large , resulting in a QR code generation error, which has been marked in red font at the beginning of this article. The get method can only transfer up to 2K large data. When the data is larger than 2K, we need to use a POST request, so in actual use, you can first Get the QR code through POST and save it as a local image, and then directly call the local image.

Method 2: Use PHP QR CODE to generate QR code

Official homepage: http://phpqrcode.sourceforge.net

Download address: http://sourceforge.net/projects/phpqrcode/

Usage: QRcode::png($data, $filename, $errorCorrectionLevel, $matrixPointSize, $margin);

* $data data

* $filename generates a QR code saving path. If it is false, it will be output directly to the browser

　*$errorCorrectionLevel error handling level L, M, Q, H; the same as the error correction level in Google API

　 * $matrixPointSize Pixels for each black point

* $margin The white border pixels around the image

Example 3: Scan the QR code to open the URL (phpqrcode)

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// Contains qrlib.php or phpqrcode.php

//Including qrlib.php needs to be put together with other files; phpqrcode.php is the merged version and only needs to include this file, but the generated image is slow and inaccurate

include('./phpqrcode/qrlib.php');

// QR code data

$data = 'http://www.111cn.net';

// Correction level: L, M, Q, H

$errorCorrectionLevel = 'L';

//Point size: 1 to 10

$matrixPointSize = 5;

QRcode::png($data, false, $errorCorrectionLevel, $matrixPointSize, 2);

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Example 2: Generate a business card QR code (phpqrcode)

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// Contains qrlib.php or phpqrcode.php

include('./phpqrcode/qrlib.php');

//Construct vcard data

$vcard =

"BEGIN:VCARD".

"nVERSION:3.0".

"nFN:王歌".

"nTEL;CELL;VOICE:18858140621".

"nTEL;WORK;VOICE:0358－2157466".

"nEMAIL:wang@qq.com".

"nURL:http://www.mailuow.com".

"nADR: No. 1750, Jianghong Road, Binjiang District, Hangzhou City, Zhejiang Province".

"nEND:VCARD";

// Correction level: L, M, Q, H

$errorCorrectionLevel = 'L';

//Point size: 1 to 10

$matrixPointSize = 4;

QRcode::png($vcard, false, $errorCorrectionLevel, $matrixPointSize, 2);

source：php.cn

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