How to generate QR code using PHP?

QR code is an indispensable way of information dissemination in modern society. It intuitively displays complex information to people in a graphical form. In website development and mobile application development, we often use QR code generation and recognition technology to facilitate users to obtain information. As a popular back-end programming language, PHP also provides convenient QR code generation and recognition functions. This article will introduce how to use PHP to generate QR codes.

1. Install the QR Code library

To generate QR codes in PHP, you need to use the QR Code encoding library. QR Code is a free and open source QR code encoding library that can be used directly in PHP projects. To use the QR Code library, you first need to download and install it in your local environment. The download address of the QR Code library is: https://github.com/khanamiryan/php-qrcode-generator. After downloading, unzip it to the root directory of the PHP project and you can use all the functions of the QR Code library.

2. Generate QR code

Using the QR Code library to generate a QR code requires calling the method in the QRcode class, for example:

require_once "qrcode/qrcode.php";
QRcode::png("http://www.baidu.com", “qrcode.png”); 

The first line in the code is Introducing the QRcode class, the second line calls the png() method of the QRcode class to generate a QR code. The first parameter is the content of the QR code that needs to be generated, and the second parameter is the storage of the generated QR code image. path. Run the above code to find the qrcode.png QR code image in the project root directory.

3. Generate QR code with logo

When generating the QR code, we can add attributes such as logo and color to it to make the generated QR code more beautiful. If you want to generate a QR code with a logo, you can use the third parameter of the png() method of the QRcode class. For example:

require_once "qrcode/qrcode.php";
QRcode::png("http://www.baidu.com", “qrcode.png”, 0, 10, 2); 

Here, the third parameter 0 represents the error correction level of the QR code, and the value range is 0-3. The larger the number, the stronger the error correction capability, and the error tolerance rate of the generated QR code. The higher it is; the fourth parameter is the width of the border, the value range is 1-10, the larger the number, the wider the border; the fifth parameter is the version number of the QR code, the value range is 1-40, the number The larger the value, the greater the storage capacity of the generated QR code information. The value here is 2, which means the QR code information storage capacity is 7, that is, it can store up to 45 characters (except Chinese characters).

If you want to generate a QR code with a logo, you can use the sixth parameter of the png() method of the QRcode class. For example:

require_once "qrcode/qrcode.php";     
QRcode::png("http://www.baidu.com", “qrcode.png”, 0, 10, 2, "logo.png"); 

In the above code, the sixth parameter is the image path of the Logo. Run this code to generate a QR code with the logo.

4. Use third-party libraries to generate QR codes

In addition to the QR Code library, there are many third-party libraries that can be used to generate QR codes. Among them, a very popular QR code generation library is the PHP QR Code library. The usage of PHP QR Code library is very similar to that of QR Code library, but there are some differences in syntax. For example:

include "phpqrcode/qrlib.php";
QRcode::png("http://www.baidu.com", “qrcode.png”);

Using the PHP QR Code library, you can also generate QR codes with logos, just add additional parameters. For example:

require "phpqrcode/qrlib.php";
QRcode::png("http://www.baidu.com", “qrcode.png”, QR_ECLEVEL_L, 10, 2, false, 0xFFFFFF, 0x000000,"logo.png");

In the above code, the seventh parameter specifies the foreground color of the QR code, the eighth parameter specifies the background color of the QR code, and the ninth parameter specifies the image path of the Logo.

Summary

PHP generated QR code is often used in projects. Both the QR Code library and the PHP QR Code library can be used to generate QR codes. Among them, the QR Code library is more lightweight and easier to use, while the PHP QR Code library is relatively rich in functions and more flexible. To generate a QR code with a logo, just add additional parameters. However, no matter which library is used to generate QR codes, you need to pay attention to the output QR code format and error tolerance, as well as control the size and color of the generated QR codes, and ultimately generate beautiful and reliable QR codes.

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