一个实用的php验证码类

 number=$number; $this->codeType=$codeType; $this->width = $width; $this->height= $height; //生成验证码函数 $this->code = $this ->createCode(); } public function __get($name){ if ($name == 'code'){ return $this->code; } return false; } /*获取验证码*/ public function getCode() { return $this->code; } /*图像资源销毁*/ public function __destruct(){ imagedestroy($this->image); } protected function createCode(){ //通过你的验证码类型生成验证码 switch ($this->codeType){ case 0: //纯数字 $code = $this->getNumberCode(); break; case 1: //纯字母的 $code = $this->getCharCode(); break; case 2: //数字和字母混合 $code = $this->getNumCharCode(); break; default: die('不支持此类验证码类型'); } return $code; } protected function getNumberCode(){ $str = join('', range(0, 9)); return substr(str_shuffle($str),0, $this->number); } protected function getCharCode(){ $str = join('', range('a', 'z')); $str = $str.strtoupper($str); return substr(str_shuffle($str),0,$this->number); } protected function getNumCharCode(){ $numstr = join('',range(0, 9)); $str =join('', range('a', 'z')); $str =$numstr.$str.strtoupper($str); return substr(str_shuffle($str), 0,$this->number); } protected function createImage(){ $this->image = imagecreatetruecolor($this->width, $this->height); } protected function fillBack(){ imagefill($this->image, 0, 0, $this->lightColor()); } /*浅色*/ protected function lightColor(){ return imagecolorallocate($this->image, mt_rand(133,255), mt_rand(133,255), mt_rand(133,255)); } /*深色*/ protected function darkColor(){ return imagecolorallocate($this->image, mt_rand(0,120), mt_rand(0,120), mt_rand(0,120)); } protected function drawChar(){ $width = ceil($this->width / $this->number); for ($i=0; $inumber;$i++){ $x = mt_rand($i*$width+5, ($i+1)*$width-10); $y = mt_rand(0, $this->height -15); imagechar($this->image, 5, $x, $y, $this->code[$i], $this->darkColor()); } } protected function drawLine(){ for ($i=0;$iimage,mt_rand(0,$this->width),mt_rand(0,$this->height),mt_rand(0,$this->width),mt_rand(0,$this->height),$this->darkColor()); } } protected function drawDisturb(){ for ($i=0;$iwidth); $y=mt_rand(0, $this->height); imagesetpixel($this->image, $x, $y, $this->lightColor()); } } protected function show(){ header('Content-Type:image/png'); imagepng($this->image); } public function outImage(){ //     创建画布 $this->createImage(); //     填充背景色 $this->fillBack(); //     将验证码字符串花到画布上 $this->drawChar(); //     添加干扰元素 $this->drawDisturb(); //     添加线条 $this->drawLine(); //     输出并显示 $this->show(); } }

 getCode(); $code->outImage(); 

    <title></title> *{margin:0px;padding:0px;} ul{ width:400px; list-style:none; margin:50px auto; } li{ padding:12px; position:relative; } label{ width:80px; display:inline-block; float:left; line-height:30px; } in<p style="color:transparent">来源gao!%daima.com搞$代*!码网</p>put[type='text'],input[type='password']{ height:30px; } img{ margin-left:10px; } input[type="submit"]{ margin-left:80px; padding:5px 10px; }   <ul> <li> <label>用户名：</label></li><li> <label>密码：</label></li><li> <label>验证码：</label></li><li> </li></ul>