PHP制作验证码

PHP制作验证码详细教程

效果：

myvcode.class.php：封装创建验证码的类

   1: <?php

   2: /*

   3: * file:myvcode.class.php

   4: * 验证码类,类名Vcode

   5: */

   6: class Vcode

   7: {

   8:     private $width;              /*验证码宽度*/

   9:     private $height;             /*验证码高度*/

  10:     private $codeNum;            /*验证码字符个数*/

  11:     private $checkCode;            /*验证码字符*/

  12:     private $image;                /*验证码资源*/

  13:     private $pixNum;            /*绘制干扰点的个数*/

  14:     private $lineNum;            /*绘制干扰线的条数*/

  15:

  16:     /*

  17:     *构造方法实例化验证码对象，并初始化数据

  18:     *@param int $width         设置默认宽度

  19:     *@param int $height     设置默认高度

  20:     *@param int $codeNum    设置验证码中的字符个数

  21:     *@param int $pixNum        设置干扰点的个数

  22:     *@param int $lineNum    设置干扰线的数量

  23:     */

  24:     function __construct($width=80,$height=40,$codeNum=4,$pixNum=40,$lineNum=5)

  25:     {

  26:         $this->width = $width;

  27:         $this->height = $height;

  28:         $this->codeNum = $codeNum;

  29:         $this->pixNum = $pixNum;

  30:         $this->lineNum = $lineNum;

  31:     }

  32:     /*内部私有方法,创建图像资源*/

  33:     private function getCreateImage()

  34:     {

  35:         $this->image = imagecreatetruecolor($this->width, $this->height);

  36:         $white = imagecolorallocate($this->image,0xff,0xff,0xff);

  37:         imagefill($this->image, 0, 0, $white);

  38:         $black = imagecolorallocate($this->image,0,0,0);

  39:         imagerectangle($this->image, 0, 0, $this->width-1, $this->height-1, $black);

  40:     }

  41:     /*内部私有方法,绘制字符，去掉o0Llz和012*/

  42:     private function createCheckCode()

  43:     {

  44:         $code = '3456789abcdefghijkmnpqrstuvwxyABCDEFGHIJKMNPQRSTUVWXY';

  45:         $this->checkCode = "";

  46:         for($i=0; $i<$this->codeNum;$i++)

  47:         {

  48:             $char = $code{rand(0,strlen($code) - 1)};

  49:             $this->checkCode .= $char;

  50:             $fontColor = imagecolorallocate($this->image, rand(0,128), rand(0,128),rand(0,128));

  51:             $fontSize = rand(3,5);

  52:             $x = rand(0,$this->width-imagefontwidth($fontSize));

  53:             $y = rand(0,$this->height-imagefontheight($fontSize));

  54:             imagechar($this->image, $fontSize, $x, $y, $char, $fontColor);

  55:         }

  56:     }

  57:     /*内部私有方法设置干扰元素*/

  58:     private function setDisturbColor()

  59:     {

  60:         /*绘制干扰点*/

  61:         for($i=0; $i<$this->pixNum; $i++)

  62:         {

  63:             $color = imagecolorallocate($this->image, rand(0,255), rand(0,255), rand(0,255));

  64:             imagesetpixel($this->image, rand(1,$this->width-2), rand(1,$this->height-2), $color);

  65:         }

  66:         /*绘制干扰线*/

  67:         for($i=0; $i<$this->lineNum; $i++)

  68:         {

  69:             $color = imagecolorallocate($this->image, rand(0,255), rand(0,255), rand(0,255));

70: imageline($this->image, rand(1,$this->width / 2), rand(1,$this->height / 2),

rand($this->width / 2,$this->width – 2), rand($this->height / 2,$this->height – 2), $color);

  71:         }

  72:     }

  73:     /*开启session保存 利用echo 输出图像*/

  74:     function __toString()

  75:     {

  76:         $_SESSION['code'] = strtoupper($this->checkCode);

  77:         $this->getCreateImage();

  78:         $this->createCheckCode();

  79:         $this->setDisturbColor();

  80:         $this->outputImg();

  81:     }

  82:     /*内部私有方法输出图像*/

  83:     private function outputImg()

  84:     {

  85:         header("content-type:image/png");

  86:         imagepng($this->image);

  87:     }

  88:     /*析构方法，释放对象*/

  89:     function __destruct()

  90:     {

  91:         imagedestroy($this->image);

  92:     }

  93: }

  94: ?>

imgcode.php输出图像

   1: <?php
   2: session_start();
   3: require_once('myvcode.class.php');
   4: echo new Vcode();
   5: ?>

test.html:同过img标签引用

   1: <img src="imgcode.php">

可以加一个a标签，用js实现换一张效果：

/*局部刷新换验证码*/
function changeCode()
{
	var imgcode = document.getElementById('code');
	var change = document.getElementById('change');
	change.onclick = function()
	{
		/*必须加后面的参数才能刷新*/
		imgcode.src='code.php?tm'+Math.random();
	}
}

code和change分别是img和a的id