PHP验证码

设计一个验证码类，在需要的时候可以随时调用

验证码类，保存为ValidateCode.class.php

 1 <?php
 2 //验证码类
 3 session_start();
 4 class ValidateCode {
 5  private $charset = 'abcdefghkmnprstuvwxyzABCDEFGHKMNPRSTUVWXYZ23456789';//随机因子
 6  private $code;//验证码
 7  private $codelen = 4;//验证码长度
 8  private $width = 130;//宽度
 9  private $height = 50;//高度
10  private $img;//图形资源句柄
11  private $font;//指定的字体
12  private $fontsize = 20;//指定字体大小
13  private $fontcolor;//指定字体颜色
14  //构造方法初始化
15  public function __construct() {
16   $this->font = './latha.ttf';//注意字体路径要写对，否则显示不了图片
17  }
18  //生成随机码
19  private function createCode() {
20   $_len = strlen($this->charset)-1;
21   for ($i=0;$i<$this->codelen;$i++) {
22    $this->code .= $this->charset[mt_rand(0,$_len)];
23   }
24  }
25  //生成背景
26  private function createBg() {
27   $this->img = imagecreatetruecolor($this->width, $this->height);
28   $color = imagecolorallocate($this->img, mt_rand(157,255), mt_rand(157,255), mt_rand(157,255));
29   imagefilledrectangle($this->img,0,$this->height,$this->width,0,$color);
30  }
31  //生成文字
32  private function createFont() {
33   $_x = $this->width / $this->codelen;
34   for ($i=0;$i<$this->codelen;$i++) {
35    $this->fontcolor = imagecolorallocate($this->img,mt_rand(0,156),mt_rand(0,156),mt_rand(0,156));
36    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[$i]);
37   }
38  }
39  //生成线条、雪花
40  private function createLine() {
41   //线条
42   for ($i=0;$i<6;$i++) {
43    $color = imagecolorallocate($this->img,mt_rand(0,156),mt_rand(0,156),mt_rand(0,156));
44    imageline($this->img,mt_rand(0,$this->width),mt_rand(0,$this->height),mt_rand(0,$this->width),mt_rand(0,$this->height),$color);
45   }
46   //雪花
47   for ($i=0;$i<100;$i++) {
48    $color = imagecolorallocate($this->img,mt_rand(200,255),mt_rand(200,255),mt_rand(200,255));
49    imagestring($this->img,mt_rand(1,5),mt_rand(0,$this->width),mt_rand(0,$this->height),'*',$color);
50   }
51  }
52  //输出
53  private function outPut() {
54  header('Content-type:image/png');
55   imagepng($this->img);
56   imagedestroy($this->img);
57  }
58  //对外生成
59  public function doimg() {
60   $this->createBg();
61   $this->createCode();
62   $this->createLine();
63   $this->createFont();
64   $this->outPut();
65  }
66  //获取验证码
67  public function getCode() {
68   return strtolower($this->code);
69  }
70 }

注意：第16行中，要修改字体的路径，否则字体图片无法显示

实现，保存为captcha.php

1 session_start();
2 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。
3 $_vc = new ValidateCode();  //实例化一个对象
4 $_vc->doimg();  
5 $_SESSION['authnum_session'] = $_vc->getCode();//验证码保存到SESSION中

页面使用

<img  title="点击刷新" src="./captcha.php" align="absbottom" onclick="this.src='captcha.php?'+Math.random();"></img>

转载自：一个漂亮的php验证码类(分享)