1.PHP生成验证码图片的核心代码:
get_code.php < ?php session_start(); //验证码类 class ValidateCode { private $charset = 'abcdefghkmnprstuvwxyzABCDEFGHKMNPRSTUVWXYZ23456789'; //随机因子 private $code; //验证码 private $codelen = 4; //验证码长度 private $width = 90; //宽度 private $height = 30; //高度 private $img; //图形资源句柄 private $font; //指定的字体 private $fontsize = 17; //指定字体大小 private $fontcolor; //指定字体颜色 //构造方法初始化 public function __construct() { $this - >font = dirname(__FILE__).'/css/font/Elephant.ttf'; //注意字体路径要写对,否则显示不了图片 } //生成随机码 private function createCode() { $_len = strlen($this - >charset) - 1; for ($i = 0; $i < $this - >codelen; $i++) { $this - >code. = $this - >charset[mt_rand(0, $_len)]; } } //生成背景 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); } //生成文字 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]); } } //生成线条、雪花 private function createLine() { //线条 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), '*', $color); } } //输出 private function outPut() { header('Content-type:image/jpeg'); imagepng($this - >img); imagedestroy($this - >img); } //对外生成 public function doimg() { $this - >createBg(); $this - >createCode(); $this - >createLine(); $this - >createFont(); $this - >outPut(); } //获取验证码 public function getCode() { return strtoupper($this - >code); } } $_vc = new ValidateCode(); //实例化一个对象 $_vc - >doimg(); $_SESSION['login_check_code'] = $_vc - >getCode(); //验证码保存到SESSION中 ? >
2.在HTML使用PHP验证码的方法
<div id="codeimg"> <img id="refresh" src="get_code.php" style="cursor:pointer"> </div>
3.提交时验证验证码是否正确
$code=strtoupper($_POST['code']); //统一都将验证码字符转为大写字母 if ($code!=$_SESSION["login_check_code"]){ echo "您获取的验证码不正确"; exit; }