PHP动态生成验证码

1 <?php
  2 /************************************************************************
  3 //FILE:ImageCode
  4 //DONE:生成动态验证码类
  5 //DATE"2010-3-31
  6 //Author:www.5dkx.com 5D开心博客
  7 ************************************************************************/
  8 class ImageCode{
  9   private $width;           //验证码图片宽度
10    private $height;         //验证码图片高度
11    private $codeNum;       //验证码字符个数
12    private $checkCode;    //验证码字符
13    private $image;       //验证码画布
14   /************************************************************************
15   // Function:构造函数
16   // Done:成员属性初始化
17   // Author:www.5dkx.com 5D开心博客
18 ************************************************************************/
19   function __construct($width=60,$height=20,$codeNum=4)
20   {
21    $this->width = $width;
22    $this->height = $height;
23    $this->codeNum = $codeNum;
24    $this->checkCode = $this->createCheckCode();
25   }
26   function showImage()
27   {
28    $this->getcreateImage();
29    $this->outputText();
30    $this->setDisturbColor();
31    $this->outputImage();
32   }
33   function getCheckCode()
34   {
35    return $this->chekCode;
36   }
37   private function getCreateImage()
38   {
39    $this->image = imagecreatetruecolor($this->width,$this->height);
40    $back = imagecolorallocate($this->image,255,255,255);
41    $border = imagecolorallocate($this->image,255,255,255);
42    imagefilledrectangle($this->image,0,0,$this->width-1,$this->height-1,$border);
43    //使用纯白色填充矩形框，这里用的话后面干扰码失效
44    /*如果想用干扰码的话使用下面的*/
45    //imagerectangle($this->image,0,0,$this->width-1,$this->height-1,$border);
46   }
47   private function createCheckCode()
48   {
49    for($i=0;$i<$this->codeNum;$i++)
50    {
51     $number = rand(0,2);
52     switch($number)
53     {
54      case 0: $rand_number = rand(48,57); break;//数字
55      case 1: $rand_number = rand(65,90);break;//大写字母
56      case 2: $rand_number = rand(97,122);break;//小写字母
57     }
58     $asc = sprintf("%c",$rand_number);
59     $asc_number = $asc_number.$asc;
60    }
61    return $asc_number;
62   }
63   private function setDisturbColor()//干扰吗设置
64   {
65    for($i=0;$i<=100;$i++)
66    {
67     //$color = imagecolorallocate($this->image,rand(0,255),rand(0,255),rand(0,255));
68     $color = imagecolorallocate($this->image,255,255,255);
69     imagesetpixel($this->image,rand(1,$this->width-2),rand(1,$this->height-2),$color);
70    }
71     //$color = imagecolorallocate($this->image,0,0,0);
72     //imagesetpixel($this->image,rand(1,$this->width-2),rand(1,$this->height-2),$color);
73    
74   
75   }
76   private function outputText()
77   {
78    //随机颜色、随机摆放、随机字符串向图像输出
79    for($i=0;$i<=$this->codeNum;$i++)
80    {
81     $bg_color = imagecolorallocate($this->image,rand(0,255),rand(0,128),rand(0,255));
82     $x = floor($this->width/$this->codeNum)*$i+3;
83     $y = rand(0,$this->height-15);
84     imagechar($this->image,5,$x,$y,$this->checkCode[$i],$bg_color);
85    }
86   }
87  
88   private function outputImage()
89   {
90    if(imagetypes()&IMG_GIF)
91    {
92     header("Content_type:image/gif");
93     imagegif($this->image);
94    }
95    elseif(imagetypes()&IMG_JPG)
96    {
97   
98     header("Content-type:image/jpeg");
99     imagejpeg($this->image,"",0.5);
100    }
101    elseif(imagetypes()&IMG_PNG)
102    {
103     header("Content-type:image/png");
104     imagejpeg($this->image);
105    }
106    elseif(imagetypes()&IMG_WBMP)
107    {
108     header("Content-type:image/vnd.wap.wbmp");
109     imagejpeg($this->image);
110    }
111    else
112    {
113     die("PHP不支持图像创建");
114    }
115   }
116  
117   function __destruct()
118   {
119    imagedestroy($this->image);
120   }
121 }
122
123 /*显示*/
124 /*******************************************************************
125 session_start();
126 $image = new ImageCode(60,20,4);
127 $image->showImage();
128 $_SESSION['ImageCode'] = $image->getCheckCode();
129 *******************************************************************/
130
131 ?>