代碼如下所示：
//驗證碼類class ValidateCode { private $charset = 'abcdefghkmnprstuvwxyzABCDEFGHKMNPRSTUVWXYZ23456789';//隨機因子 private $code;//驗證碼 private $codelen = 4;//驗證碼長度 private $width = 130;//寬度 private $height = 50;//高度 private $img;//圖形資源控制代碼 private $font;//指定的字型 private $fontsize = 20;//指定字型大小 private $fontcolor;//指定字型顏色 //構造方法初始化 public function __construct() { $this->font = dirname(__FILE__).'/font/elephant.ttf';//注意字型路徑要寫對，否則顯示不了圖片 } //產生隨機碼 private function createCode() { $_len = strlen($this->charset)-1; for ($i=0;$i<$this->codelen;$i++) { $this->code .= $this->charset[mt_rand(0,$_len)]; } } //產生背景 private function createBg() { $this->img = imagecreatetruecolor($this->width, $this->height); $color = imagecolorallocate($this->img, mt_rand(157,255), mt_rand(157,255), mt_rand(157,255)); imagefilledrectangle($this->img,0,$this->height,$this->width,0,$color); } //產生文字 private function createFont() { $_x = $this->width / $this->codelen; for ($i=0;$i<$this->codelen;$i++) { $this->fontcolor = imagecolorallocate($this->img,mt_rand(0,156),mt_rand(0,156),mt_rand(0,156)); imagettftext($this->img,$this->fontsize,mt_rand(-30,30),$_x*$i+mt_rand(1,5),$this->height / 1.4,$this->fontcolor,$this->font,$this->code[$i]); } } //產生線條、雪花 private function createLine() { //線條 for ($i=0;$i<6;$i++) { $color = imagecolorallocate($this->img,mt_rand(0,156),mt_rand(0,156),mt_rand(0,156)); imageline($this->img,mt_rand(0,$this->width),mt_rand(0,$this->height),mt_rand(0,$this->width),mt_rand(0,$this->height),$color); } //雪花 for ($i=0;$i<100;$i++) { $color = imagecolorallocate($this->img,mt_rand(200,255),mt_rand(200,255),mt_rand(200,255)); imagestring($this->img,mt_rand(1,5),mt_rand(0,$this->width),mt_rand(0,$this->height),'*',$color); } } //輸出 private function outPut() { header('Content-type:image/png'); imagepng($this->img); imagedestroy($this->img); } //對外產生 public function doimg() { $this->createBg(); $this->createCode(); $this->createLine(); $this->createFont(); $this->outPut(); } //擷取驗證碼 public function getCode() { return strtolower($this->code); }}
使用方法：
1、先把驗證碼類儲存為一個名為 ValidateCode.class.php 的檔案；
2、建立一個名為 captcha.php 的檔案進行調用該類；
captcha.php
3、引用到頁面中，代碼如下：
4、一個完整的驗證頁面，代碼如下：
<?phpsession_start();//在頁首先要開啟session,//error_reporting(2047);session_destroy();//將session去掉，以每次都能取新的session值;//用seesion 效果不錯，也很方便?><html><head><title>session 圖片驗證執行個體</title><style type="text/css">#login p{margin-top: 15px;line-height: 20px;font-size: 14px;font-weight: bold;}#login img{cursor:pointer;}form{margin-left:20px;}</style></head> <body><form id="login" action="" method="post"><p>此例為session驗證執行個體</p><p><span>驗證碼：</span><input type="text" name="validate" value="" size=10> <img title="點擊重新整理" src="./captcha.php" align="absbottom" onclick="this.src='captcha.php?'+Math.random();"></img></p><p><input type="submit"></p></form><?php//列印上一個session;//echo "上一個session：<b>".$_SESSION["authnum_session"]."</b><br>";$validate="";if(isset($_POST["validate"])){$validate=$_POST["validate"];echo "您剛才輸入的是：".$_POST["validate"]."<br>狀態：";if($validate!=$_SESSION["authnum_session"]){//判斷session值與使用者輸入的驗證碼是否一致;echo "<font color=red>輸入有誤</font>"; }else{echo "<font color=green>通過驗證</font>"; }} ?>Start building with 50+ products and up to 12 months usage for Elastic Compute Service
1 on 1 presale consultation
24/7 Technical Support 6 Free Tickets per Quarter Faster Response
Alibaba Cloud offers highly flexible support services tailored to meet your exact needs.
A comprehensive suite of global cloud computing services to power your business
Payment Methods We Support
