How to generate image verification code in php_php skills
This article shares with you the method of generating image verification code in PHP for your reference. The specific content is as follows
First, randomly select a fixed number of characters from the specified character set, draw them on the canvas in an irregular way, then add some interference points and interference elements appropriately, and finally output the picture, and a new verification code will be Done.
The front-end code is as follows:
<!DOCTYPE html> <html> <head> <meta http-equiv="content-type" content="text/html;charset=utf-8"> <title>This is a test!</title> <link rel="stylesheet" type="text/css" href="css/bootstrap.min.css"> </head> <body> <form name="form"> <input type="text" placeholder="账号"/><br/> <input type="password" placeholder="密码"/><br/> <input type="text" placeholder="验证码"/> <img src="/static/imghwm/default1.png" data-src="libs/verification.php" class="lazy" id="verImg"/ alt="How to generate image verification code in php_php skills" > <a href="#" class="change" onclick="changeVer()">点击刷新</a><br/> <input type="submit" value="登录"/> </form> <script type="text/javascript"> //刷新验证码 function changeVer(){ document.getElementById("verImg").src="libs/verification.php?tmp="+Math.random(); } </script> </body> </html>
The code for the php script file verification code is as follows:
<?php session_start(); //开启session记录验证码数据 vCode(4, 15);//设置验证码的字符个数和图片基础宽度 //vCode 字符数目,字体大小,图片宽度、高度 function vCode($num = 4, $size = 20, $width = 0, $height = 0) { !$width && $width = $num * $size * 4 / 5 + 15; !$height && $height = $size + 10; //设置验证码字符集合 $str = "23456789abcdefghijkmnpqrstuvwxyzABCDEFGHIJKLMNPQRSTUVW"; //保存获取的验证码 $code = ''; //随机选取字符 for ($i = 0; $i < $num; $i++) { $code .= $str[mt_rand(0, strlen($str)-1)]; } //创建验证码画布 $im = imagecreatetruecolor($width, $height); //背景色 $back_color = imagecolorallocate($im, mt_rand(0,100),mt_rand(0,100), mt_rand(0,100)); //文本色 $text_color = imagecolorallocate($im, mt_rand(100, 255), mt_rand(100, 255), mt_rand(100, 255)); imagefilledrectangle($im, 0, 0, $width, $height, $back_color); // 画干扰线 for($i = 0;$i < 5;$i++) { $font_color = imagecolorallocate($im, mt_rand(0, 255), mt_rand(0, 255), mt_rand(0, 255)); imagearc($im, mt_rand(- $width, $width), mt_rand(- $height, $height), mt_rand(30, $width * 2), mt_rand(20, $height * 2), mt_rand(0, 360), mt_rand(0, 360), $font_color); } // 画干扰点 for($i = 0;$i < 50;$i++) { $font_color = imagecolorallocate($im, mt_rand(0, 255), mt_rand(0, 255), mt_rand(0, 255)); imagesetpixel($im, mt_rand(0, $width), mt_rand(0, $height), $font_color); } //随机旋转角度数组 $array=array(5,4,3,2,1,0,-1,-2,-3,-4,-5); // 输出验证码 // imagefttext(image, size, angle, x, y, color, fontfile, text) @imagefttext($im, $size , array_rand($array), 12, $size + 6, $text_color, 'c:\WINDOWS\Fonts\simsun.ttc', $code); $_SESSION["VerifyCode"]=$code; //no-cache在每次请求时都会访问服务器 //max-age在请求1s后再次请求会再次访问服务器,must-revalidate则第一发送请求会访问服务器,之后不会再访问服务器 // header("Cache-Control: max-age=1, s-maxage=1, no-cache, must-revalidate"); header("Cache-Control: no-cache"); header("Content-type: image/png;charset=gb2312"); //将图片转化为png格式 imagepng($im); imagedestroy($im); } ?>
Rendering:
The above is the entire content of this article. I hope it will be helpful for everyone to learn PHP programming and learn to write PHP image verification codes

ThebestapproachforsendingemailsinPHPisusingthePHPMailerlibraryduetoitsreliability,featurerichness,andeaseofuse.PHPMailersupportsSMTP,providesdetailederrorhandling,allowssendingHTMLandplaintextemails,supportsattachments,andenhancessecurity.Foroptimalu

The reason for using Dependency Injection (DI) is that it promotes loose coupling, testability, and maintainability of the code. 1) Use constructor to inject dependencies, 2) Avoid using service locators, 3) Use dependency injection containers to manage dependencies, 4) Improve testability through injecting dependencies, 5) Avoid over-injection dependencies, 6) Consider the impact of DI on performance.

PHPperformancetuningiscrucialbecauseitenhancesspeedandefficiency,whicharevitalforwebapplications.1)CachingwithAPCureducesdatabaseloadandimprovesresponsetimes.2)Optimizingdatabasequeriesbyselectingnecessarycolumnsandusingindexingspeedsupdataretrieval.

ThebestpracticesforsendingemailssecurelyinPHPinclude:1)UsingsecureconfigurationswithSMTPandSTARTTLSencryption,2)Validatingandsanitizinginputstopreventinjectionattacks,3)EncryptingsensitivedatawithinemailsusingOpenSSL,4)Properlyhandlingemailheaderstoa

TooptimizePHPapplicationsforperformance,usecaching,databaseoptimization,opcodecaching,andserverconfiguration.1)ImplementcachingwithAPCutoreducedatafetchtimes.2)Optimizedatabasesbyindexing,balancingreadandwriteoperations.3)EnableOPcachetoavoidrecompil

DependencyinjectioninPHPisadesignpatternthatenhancesflexibility,testability,andmaintainabilitybyprovidingexternaldependenciestoclasses.Itallowsforloosecoupling,easiertestingthroughmocking,andmodulardesign,butrequirescarefulstructuringtoavoidover-inje

PHP performance optimization can be achieved through the following steps: 1) use require_once or include_once on the top of the script to reduce the number of file loads; 2) use preprocessing statements and batch processing to reduce the number of database queries; 3) configure OPcache for opcode cache; 4) enable and configure PHP-FPM optimization process management; 5) use CDN to distribute static resources; 6) use Xdebug or Blackfire for code performance analysis; 7) select efficient data structures such as arrays; 8) write modular code for optimization execution.

OpcodecachingsignificantlyimprovesPHPperformancebycachingcompiledcode,reducingserverloadandresponsetimes.1)ItstorescompiledPHPcodeinmemory,bypassingparsingandcompiling.2)UseOPcachebysettingparametersinphp.ini,likememoryconsumptionandscriptlimits.3)Ad


Hot AI Tools

Undresser.AI Undress
AI-powered app for creating realistic nude photos

AI Clothes Remover
Online AI tool for removing clothes from photos.

Undress AI Tool
Undress images for free

Clothoff.io
AI clothes remover

Video Face Swap
Swap faces in any video effortlessly with our completely free AI face swap tool!

Hot Article

Hot Tools

ZendStudio 13.5.1 Mac
Powerful PHP integrated development environment

WebStorm Mac version
Useful JavaScript development tools

SAP NetWeaver Server Adapter for Eclipse
Integrate Eclipse with SAP NetWeaver application server.

SublimeText3 English version
Recommended: Win version, supports code prompts!

MinGW - Minimalist GNU for Windows
This project is in the process of being migrated to osdn.net/projects/mingw, you can continue to follow us there. MinGW: A native Windows port of the GNU Compiler Collection (GCC), freely distributable import libraries and header files for building native Windows applications; includes extensions to the MSVC runtime to support C99 functionality. All MinGW software can run on 64-bit Windows platforms.
