Share three methods of generating QR codes in PHP-PHP Tutorial-php.cn

The simplest and most practical Google open source method, but the response is a bit slow

1.Google open api

The code is as follows:

$urlToEncode="http://www.helloweba.com";   
generateQRfromGoogle($urlToEncode);   
/**  
 * google api 二维码生成【QRcode可以存储最多4296个字母数字类型的任意文本，具体可以查看二维码数据格式】  
 * @param string $chl 二维码包含的信息，可以是数字、字符、二进制信息、汉字。  
 不能混合数据类型，数据必须经过UTF-8 URL-encoded  
 * @param int $widhtHeight 生成二维码的尺寸设置  
 * @param string $EC_level 可选纠错级别，QR码支持四个等级纠错，用来恢复丢失的、读错的、模糊的、数据。  
 *                            L-默认：可以识别已损失的7%的数据  
 *                            M-可以识别已损失15%的数据  
 *                            Q-可以识别已损失25%的数据  
 *                            H-可以识别已损失30%的数据  
 * @param int $margin 生成的二维码离图片边框的距离  
 */   
function generateQRfromGoogle($chl,$widhtHeight ='150',$EC_level='L',$margin='0')   
{   
    $chl = urlencode($chl);   
    echo '<img src="http://chart.apis.google.com/chart?chs=&#39;.$widhtHeight.&#39;x&#39;.$widhtHeight.&#39;   
    &cht=qr&chld=&#39;.$EC_level.&#39;|&#39;.$margin.&#39;&chl=&#39;.$chl.&#39;" alt="QR code" widhtHeight="&#39;.$widhtHeight.&#39;   
    " widhtHeight="&#39;.$widhtHeight.&#39;"/>';   
}

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2.php class library PHP QRCode

Address: http://phpqrcode.sourceforge.net/
Download: http://sourceforge.net/projects/phpqrcode/
After downloading the class library provided by the official website, you only need to use phpqrcode.php to generate the QR code. Of course, your PHP environment must enable support for GD2. phpqrcode.php provides a key png() method, in which the parameter $frame represents the generated information text; the parameter $filename Indicates whether to output a QR code image file (file path, including image name and suffix), the default is no; the parameter $pixelPerPoint indicates the fault tolerance rate, that is, the covered area can still recognize the parameter, $ outerFrame indicates the size of the generated image, the default is 4; the parameter $saveandprint indicates whether to save the QR code.

The code is as follows:

public static function png($frame, $filename = false, $pixelPerPoint = 4, $outerFrame = 4,$saveandprint=FALSE) 
        {
            $image = self::image($frame, $pixelPerPoint, $outerFrame);
            
            if ($filename === false) {
                Header("Content-type: image/png");
                ImagePng($image);
            } else {
                if($saveandprint===TRUE){
                    ImagePng($image, $filename);
                    header("Content-type: image/png");
                    ImagePng($image);
                }else{
                    ImagePng($image, $filename);
                }
            }
            
            ImageDestroy($image);
        }

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Calling PHP QR Code:

<?php
include &#39;phpqrcode.php&#39;;   //只需要phpqrcode一个文件即可，下载的里面其他的没什么用
QRcode::png(&#39;http://www.baidu.com&#39;);

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In actual application, we will add our own LOGO in the middle of the QR code to enhance the publicity effect . So how to generate a QR code containing a logo? In fact, the principle is very simple. First use PHP QRCode to generate a QR code image, and then use PHP's image related functions to add the pre-prepared logo image to the newly generated original QR code image. in the middle of the QR code image, and then regenerate a new QR code image.

<?php
include &#39;./phpqrcode.php&#39;;
QRcode::png(&#39;http://www.baidu.com&#39;,&#39;qrcode.png&#39;,2,10,true);
$logo = &#39;logo.jpg&#39;;//准备好的logo图片
$QR = &#39;qrcode.png&#39;;//已经生成的原始二维码图
if ($logo !== FALSE) {
    $QR = imagecreatefromstring(file_get_contents($QR));
    $logo = imagecreatefromstring(file_get_contents($logo));
    $QR_width = imagesx($QR);//二维码图片宽度
    $QR_height = imagesy($QR);//二维码图片高度
    $logo_width = imagesx($logo);//logo图片宽度
    $logo_height = imagesy($logo);//logo图片高度
    $logo_qr_width = $QR_width / 5;
    $scale = $logo_width/$logo_qr_width;
    $logo_qr_height = $logo_height/$scale;
    $from_width = ($QR_width - $logo_qr_width) / 2;
    //重新组合图片并调整大小
    imagecopyresampled($QR, $logo, $from_width, $from_width, 0, 0, $logo_qr_width,
    $logo_qr_height, $logo_width, $logo_height);
}
//输出图片
imagepng($QR, &#39;newcode.png&#39;);
echo &#39;![](./newcode.png)&#39;;

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For the second method: If $filename is not used and the second parameter is false, the QR code image will not be saved, but will be output directly.
There are also some if you like: libqrencode and QRcode Perl CGI & PHP scripts QR code generation plug-in. If you like it, you can also take a look.

3. The jquery-based QR code generation plug-in qrcode can generate the corresponding QR code by calling the plug-in on the page.
qrcode actually uses jQuery to achieve graphics rendering and drawing, supporting canvas (HTML5) and table.
You can go to https://github.com/jeromeetienne/jquery-qrcode to get the latest code.

How to use

(1), first add the jquery library file and qrcode plug-in to the page.

<script type="text/javascript" src="jquery.js"></script> 
<script type="text/javascript" src="jquery.qrcode.min.js"></script>

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(2). Add the following code to the page where the QR code needs to be displayed:

<p id="code"></p>

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(3). Call the qrcode plug-in.
qrcode supports canvas and table methods for image rendering. The canvas method is used by default, which is the most efficient. Of course, the browser must support html5. Directly call it as follows:

$('#code').qrcode("http://www.helloweba.com"); //任意字符串

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You can also call it in the following way:

$("#code").qrcode({ 
    render: "table", //table方式 
    width: 200, //宽度 
    height:200, //高度 
    text: "www.helloweba.com" //任意内容 
});

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This will generate a QR code directly on the page, and you can use the "scan" function of your mobile phone to read it. Get the QR code information.

Recognize Chinese

When we tested, we found that the QR code with Chinese content could not be recognized. By searching various information, we learned that jquery-qrcode uses the charCodeAt() method. Code conversion. This method will obtain its Unicode encoding by default. If there is Chinese content, the string must be converted to UTF-8 before generating the QR code, and then the QR code will be generated. You can convert Chinese strings by the following function:

function toUtf8(str) {    
    var out, i, len, c;    
    out = "";    
    len = str.length;    
    for(i = 0; i < len; i++) {    
        c = str.charCodeAt(i);    
        if ((c >= 0x0001) && (c <= 0x007F)) {    
            out += str.charAt(i);    
        } else if (c > 0x07FF) {    
            out += String.fromCharCode(0xE0 | ((c >> 12) & 0x0F));    
            out += String.fromCharCode(0x80 | ((c >>  6) & 0x3F));    
            out += String.fromCharCode(0x80 | ((c >>  0) & 0x3F));    
        } else {    
            out += String.fromCharCode(0xC0 | ((c >>  6) & 0x1F));    
            out += String.fromCharCode(0x80 | ((c >>  0) & 0x3F));    
        }    
    }    
    return out;    
}

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Example below:

var str = toUtf8("随便来点啥"); 
$('#code').qrcode(str);

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