This time I will bring you a detailed explanation of the QR code generated by the phpqrcode class. What are the precautions for generating the QR code by the phpqrcode class. The following is a practical case, let's take a look.

The example in this article describes how PHP generates QR codes based on the phpqrcode class. Share it with everyone for your reference, the details are as follows:

It is quite difficult to use PHP language to generate QR codes. Of course, the interface for generating QR code images is called (for example: Liantu.com http://www .liantu.com/ interface), if you write the code to generate it yourself, you really have no way to start. However, we can use phpqrcode, a ready-made class file, PHP QR code generation class library, which can easily generate QR codes.

Preliminary preparation:

1.phpqrcode classFile download, download address: https://sourceforge.net /projects/phpqrcode/
2. The PHP environment must enable GD2 extension library support (usually enabled)

Interpretation of method:

The downloaded class file is a compressed package, which contains many files and demonstration programs. We only need the phpqrcode.php file inside to generate the QR code. It is a collection file of multiple classes. We need to use the png() method (line 3090) of the QRcode class (line 2963) inside:

public?static?function?png($text,?$outfile?=?false,?$level?=?QR_ECLEVEL_L,?$size?=?3,?$margin?=?4,?$saveandprint=false)
{
??$enc?=?QRencode::factory($level,?$size,?$margin);
??return?$enc->encodePNG($text,?$outfile,?$saveandprint=false);
}

The first parameter$text : The content contained in the QR code can be links, text, json strings, etc.;
The second parameter $outfile: The default is false, no file is generated, and only the second parameter is The QR code image is returned as output; otherwise, the file name and path to store the generated QR code image need to be given;
The third parameter$level: The default is L, the values ??that can be passed by this parameter are L(QR_ECLEVEL_L, 7%), M(QR_ECLEVEL_M, 15%), Q(QR_ECLEVEL_Q, 25%), H(QR_ECLEVEL_H, 30%), this parameter controls the error tolerance rate of the QR code. Different parameters indicate that the QR code can be The percentage of the area covered, that is, the covered area can still be identified;
The fourth parameter$size: Controls the size of the generated image, the default is 4;
The fifth parameter$margin: Control the size of the blank area for generating QR codes;
The sixth parameter $saveandprint: Save the QR code image and display it, $outfile must pass the image path;

Usage example:

1. Generate QR code (generate image file)

//?1.?生成原始的二維碼(生成圖片文件)
function?scerweima($url=''){
??require_once?'phpqrcode.php';
??$value?=?$url;?????????//二維碼內(nèi)容
??$errorCorrectionLevel?=?'L';??//容錯級別
??$matrixPointSize?=?5;??????//生成圖片大小
??//生成二維碼圖片
??$filename?=?'qrcode/'.microtime().'.png';
??QRcode::png($value,$filename?,?$errorCorrectionLevel,?$matrixPointSize,?2);
??$QR?=?$filename;????????//已經(jīng)生成的原始二維碼圖片文件
??$QR?=?imagecreatefromstring(file_get_contents($QR));
??//輸出圖片
??imagepng($QR,?'qrcode.png');
??imagedestroy($QR);
??return?'<img src="qrcode.png" alt="使用微信掃描支付">';
}
//調(diào)用查看結(jié)果
echo?scerweima('https://www.baidu.com');

2. Add logo to the generated QR code (generate image file)

//2.?在生成的二維碼中加上logo(生成圖片文件)
function?scerweima1($url=''){
??require_once?'phpqrcode.php';
??$value?=?$url;?????????//二維碼內(nèi)容
??$errorCorrectionLevel?=?'H';??//容錯級別
??$matrixPointSize?=?6;??????//生成圖片大小
??//生成二維碼圖片
??$filename?=?'qrcode/'.microtime().'.png';
??QRcode::png($value,$filename?,?$errorCorrectionLevel,?$matrixPointSize,?2);
??$logo?=?'qrcode/logo.jpg';?//準(zhǔn)備好的logo圖片
??$QR?=?$filename;??????//已經(jīng)生成的原始二維碼圖
??if?(file_exists($logo))?{
????$QR?=?imagecreatefromstring(file_get_contents($QR));????//目標(biāo)圖象連接資源。
????$logo?=?imagecreatefromstring(file_get_contents($logo));??//源圖象連接資源。
????$QR_width?=?imagesx($QR);??????//二維碼圖片寬度
????$QR_height?=?imagesy($QR);?????//二維碼圖片高度
????$logo_width?=?imagesx($logo);????//logo圖片寬度
????$logo_height?=?imagesy($logo);???//logo圖片高度
????$logo_qr_width?=?$QR_width?/?4;???//組合之后logo的寬度(占二維碼的1/5)
????$scale?=?$logo_width/$logo_qr_width;??//logo的寬度縮放比(本身寬度/組合后的寬度)
????$logo_qr_height?=?$logo_height/$scale;?//組合之后logo的高度
????$from_width?=?($QR_width?-?$logo_qr_width)?/?2;??//組合之后logo左上角所在坐標(biāo)點(diǎn)
????//重新組合圖片并調(diào)整大小
????/*
?????*?imagecopyresampled()?將一幅圖像(源圖象)中的一塊正方形區(qū)域拷貝到另一個圖像中
?????*/
????imagecopyresampled($QR,?$logo,?$from_width,?$from_width,?0,?0,?$logo_qr_width,$logo_qr_height,?$logo_width,?$logo_height);
??}
??//輸出圖片
??imagepng($QR,?'qrcode.png');
??imagedestroy($QR);
??imagedestroy($logo);
??return?'<img src="qrcode.png" alt="使用微信掃描支付">';
}
//調(diào)用查看結(jié)果
echo?scerweima1('https://www.baidu.com');

3. Generate QR code (do not generate image file)

//3.?生成原始的二維碼(不生成圖片文件)
function?scerweima2($url=''){
??require_once?'phpqrcode.php';
??$value?=?$url;?????????//二維碼內(nèi)容
??$errorCorrectionLevel?=?'L';??//容錯級別
??$matrixPointSize?=?5;??????//生成圖片大小
??//生成二維碼圖片
??$QR?=?QRcode::png($value,false,$errorCorrectionLevel,?$matrixPointSize,?2);
}
//調(diào)用查看結(jié)果
scerweima2('https://www.baidu.com');

The first two methods will generate a QR code image locally every time they are called. The third method will directly output the QR code to the browser without generating a file.

I believe you have mastered the method after reading the case in this article. For more exciting information, please pay attention to other related articles on the php Chinese website!

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The above is the detailed content of Detailed explanation of phpqrcode class to generate QR code. For more information, please follow other related articles on the PHP Chinese website!