验证码

  1 <?php
  2 
  3 /**
  4  * @PHP验证码类
  5  * 使用方法：
  6  * $image=new Captcha();
  7  * $image->config(‘宽度‘,‘高度‘,‘字符个数‘,‘验证码session索引‘);
  8  * $image->create();//这样就会向浏览器输出一张图片
  9  * //所有参数都可以省略，
 10  * 默认是：宽80 高20 字符数4 验证码session索引captcha_code
 11  * 第四个参数即把验证码存到$_SESSION[‘captcha_code‘]
 12  * 最简单使用示例:
 13  * $image=new Captcha();
 14  * $image->create();//这样就会向浏览器输出一张图片
 15  */
 16 class Captcha
 17 {
 18   private $width=80,$height=20,$codenum=4;
 19   public $checkcode;   //产生的验证码
 20   private $checkimage;  //验证码图片
 21   private $disturbColor = ‘‘; //干扰像素
 22   private $session_flag=‘captcha_code‘;//存到session中的索引
 23 //尝试开始session
 24   function __construct(){
 25     @session_start();
 26   }
 27   /*
 28   * 参数：（宽度，高度，字符个数）
 29   */
 30   function config($width=‘80‘,$height=‘20‘,$codenum=‘4‘,$session_flag=‘captcha_code‘)
 31   {
 32     $this->width=$width;
 33     $this->height=$height;
 34     $this->codenum=$codenum;
 35     $this->session_flag=$session_flag;
 36   }
 37   function create()
 38   {
 39     //输出头
 40     $this->outFileHeader();
 41     //产生验证码
 42     $this->createCode();
 43     //产生图片
 44     $this->createImage();
 45     //设置干扰像素
 46     $this->setDisturbColor();
 47     //往图片上写验证码
 48     $this->writeCheckCodeToImage();
 49     imagepng($this->checkimage);
 50     imagedestroy($this->checkimage);
 51     $_SESSION[$this->session_flag]=$this->checkcode;
 52   }
 53   /*
 54     * @brief 输出头
 55     */
 56   private function outFileHeader()
 57   {
 58     header ("Content-type: image/png");
 59   }
 60   /**
 61    * 产生验证码
 62    */
 63   private function createCode()
 64   {
 65     $this->checkcode = strtoupper(substr(md5(rand()),0,$this->codenum));
 66   }
 67   /**
 68    * 产生验证码图片
 69    */
 70   private function createImage()
 71   {
 72     $this->checkimage = @imagecreate($this->width,$this->height);
 73     $back = imagecolorallocate($this->checkimage,255,255,255);
 74     $border = imagecolorallocate($this->checkimage,0,0,0);
 75     imagefilledrectangle($this->checkimage,0,0,$this->width - 1,$this->height - 1,$back); // 白色底
 76     imagerectangle($this->checkimage,0,0,$this->width - 1,$this->height - 1,$border);  // 黑色边框
 77   }
 78   /**
 79    * 设置图片的干扰像素
 80    */
 81   private function setDisturbColor()
 82   {
 83     for ($i=0;$i<=200;$i++)
 84     {
 85       $this->disturbColor = imagecolorallocate($this->checkimage, rand(0,255), rand(0,255), rand(0,255));
 86       imagesetpixel($this->checkimage,rand(2,128),rand(2,38),$this->disturbColor);
 87     }
 88   }
 89   /**
 90    * 在验证码图片上逐个画上验证码
 91    */
 92   private function writeCheckCodeToImage()
 93   {
 94     for ($i=0;$i<$this->codenum;$i++)
 95     {
 96       $bg_color = imagecolorallocate ($this->checkimage, rand(0,255), rand(0,128), rand(0,255));
 97       $x = floor($this->width/$this->codenum)*$i;
 98       $y = rand(0,$this->height-15);
 99       imagechar ($this->checkimage, rand(5,8), $x+5, $y, $this->checkcode[$i], $bg_color);
100     }
101   }
102   function __destruct()
103   {
104     unset($this->width,$this->height,$this->codenum,$this->session_flag);
105   }
106 }
107 ?>

<?php 
require_once(‘captcha.php‘);
$image =  new Captcha();
$image ->create();

 1 <?php 
 2 ob_start();
 3 session_start();
 4 if(!empty($_POST)){
 5     $answer = $_POST[‘answer‘];
 6     $captcha = $_SESSION[‘captcha_code‘];
 7     if($answer !== $captcha){
 8         echo "<script>alert(‘验证码错误‘);history.go(-1);</script>";
 9         die;
10     }
11 
12 
13 
14 ?>
15 
16 
17 <form name="login1" method="post" action=" " onsubmit="return checklogin1();">            
18             <ul class="loginRegist" style="margin-top: 85px;">
19                 <li>
20                     <span class="titleOne" style=""> 
21                         <label for="username">账户</label>
22                     </span>
23                     <span style="width: 200px;position: relative;" class="titleInput">
24                         <input id="username" name="username" class="regUserName" type="text" value="" placeholder="" />
25                     </span>
26                 
27                 </li>               
28                 <li>
29                     <span class="titleOne" style="">
30                         <label for="password">密码</label>
31                     </span>
32                     <span class="titleInput" style="position: relative;">
33                         <input id="password" name="password"  type="password" placeholder="" maxlength="32" /> 
34                     </span>
35                     
36                 </li>
37                
38                 <li>
39                     <span class="titleOne"><label for="username">问题验证</label></span>
40                     <span style="width: 370px;display: inline-block;text-align: left;">
41                         <span class="titleInput"><input name="answer" id="answer"  class="codeInput" type="text"/></span>
42                         <!-- <a class="msgCodeBindBtnA" style="color: rgb(153, 153, 153);font-size: 13px;">23+51=？</a> -->
43                         <img src="diaocaptcha.php" alt="验证码" onclick="this.src=‘diaocaptcha.php?=‘+Math.random()" />
44                     </span>
45                 </li>               
46             </ul>
47             <div class="registCue">
48                  <input class="regeditButton disagree" type="submit" value="登   陆">
49             </div>
50 </form>