漂亮的 PHP 验证码类

<?php
	//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 = 130;//宽度
		private $height = 50;//高度
		private $img;//图形资源句柄
		private $font;//指定的字体
		private $fontsize = 20;//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 = ROOT_PATH.'/font/elephant.ttf';
		}

		//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() {
			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);
			}
			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/png');
			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 strtolower($this->code);
		}

}

?>

输出实例：

使用方法：

1、先把验证码类保存为一个名为 ValidateCode.class.php 的文件；

2、做一个名为 code.php 的文件进行调用该类；

code.php

<?php
	require './ValidateCode.class.php';  //先把类包含进来，实际路径根据实际情况进行修改。
	$_vc = new ValidateCode();		//实例化一个对象
	$_vc->doimg();			
	$_SESSION['code'] = $_vc->getCode();//验证码保存到SESSION中
?>

3、引用到页面中，代码如下：

<pre name="code" class="html"><label><img src="./code.php" onclick="javascript:this.src='./code.php?tm='+Math.random();" /></label></pre>