教程吧

本文实例讲述了PHP生成图片验证码功能。分享给大家供大家参考，具体如下：

只是简单的用随机函数实现了图片的生成，没有对验证的整个流程做介绍。

代码如下：

<?php /** * Created by JetBrains PhpStorm. * User: lee * To change this template use File | Settings | File Templates. */ header("content-type:image/jpg"); $validateLength=4; $strToDraw=""; $chars=[ "0","1","2","3","4", "5","6","7","8","9", "a","b","c","d","e","f","g", "h","i","j","k","l","m","n", "o","p","q","r","s","t", "u","v","w","x","y","z", "A","B","C","D","E","F","G", "H","I","J","K","L","M","N", "O","P","Q","R","S","T", "U","V","W","X","Y","Z" ]; $imgW=80; $imgH=25; $imgRes=imagecreate($imgW,$imgH); $imgColor=imagecolorallocate($imgRes,255,255,100); $color=imagecolorallocate($imgRes,0,0,0); for($i=0;$i<$validateLength;$i++){ $rand=rand(1,58); $strToDraw=$strToDraw." ".$chars[$rand]; } imagestring($imgRes,5,0,5,$strToDraw,$color); for($i=0;$i<100;$i++){ imagesetpixel($imgRes,rand(0,$imgW),rand(0,$imgH),$color); } imagejpg($imgRes); imagedestroy($imgRes);

运行效果如下：