php ci框架验证码实例分析

php ci框架验证码实例分析

php代码:

复制代码 代码如下:

<?php

class Captcha_code

{

var $width='60';

var $num='4';

var $height='20';

var $name='randcode';

public function __construct($conf="")

{

if($conf!="")

{

foreach($conf as $key=>$value)

{

$this->$key=$value;

}

}

}

function show()

{

Header("Content-type: image/gif");

/*

* 初始化

*/

$border = 0; //是否要边框 1要:0不要

$how = $this->num; //验证码位数

$w = $this->width; //图片宽度

$h = $this->height; //图片高度

$fontsize = 5; //字体大小

$alpha = "abcdefghijkmnopqrstuvwxyz"; //验证码内容1:字母

$number = "023456789"; //验证码内容2:数字

$randcode = ""; //验证码字符串初始化

srand((double)microtime()*1000000); //初始化随机数种子

$im = ImageCreate($w, $h); //创建验证图片

/*

* 绘制基本框架

*/

$bgcolor = ImageColorAllocate($im, 255, 255, 255); //设置背景颜色

ImageFill($im, 0, 0, $bgcolor); //填充背景色

if($border)

{

$black = ImageColorAllocate($im, 0, 0, 0); //设置边框颜色

ImageRectangle($im, 0, 0, $w-1, $h-1, $black);//绘制边框

}

/*

* 逐位产生随机字符

*/

for($i=0; $i<$how; $i++)

{

$alpha_or_number = mt_rand(0, 1); //字母还是数字

$str = $alpha_or_number ? $alpha : $number;

$which = mt_rand(0, strlen($str)-1); //取哪个字符

$code = substr($str, $which, 1); //取字符

$j = !$i ? 4 : $j+15; //绘字符位置

$color3 = ImageColorAllocate($im, mt_rand(0,100), mt_rand(0,100), mt_rand(0,100)); //字符随即颜色

ImageChar($im, $fontsize, $j, 3, $code, $color3); //绘字符

$randcode .= $code; //逐位加入验证码字符串

}

/*

* 添加干扰

*/

for($i=0; $i<5; $i++)//绘背景干扰线

{

$color1 = ImageColorAllocate($im, mt_rand(0,255), mt_rand(0,255), mt_rand(0,255)); //干扰线颜色

ImageArc($im, mt_rand(-5,$w), mt_rand(-5,$h), mt_rand(20,300), mt_rand(20,200), 55, 44, $color1); //干扰线

}

for($i=0; $i<$how*15; $i++)//绘背景干扰点

{

$color2 = ImageColorAllocate($im, mt_rand(0,255), mt_rand(0,255), mt_rand(0,255)); //干扰点颜色

ImageSetPixel($im, mt_rand(0,$w), mt_rand(0,$h), $color2); //干扰点

}

//把验证码字符串写入session

//$this->session->set_userdata(array($this->name=>$randcode));

$_SESSION[$this->name]=$randcode;

/*绘图结束*/

Imagegif($im);

ImageDestroy($im);

/*绘图结束*/

}

}

?>

调用php代码:

复制代码 代码如下:

function verify_image() {

$conf['name'] = 'verify_code'; //作为配置参数

$this->load->library('lib_captcha', $conf);

$this->lib_captcha->show();

$yzm_session = $this->session->userdata('verify_code');

echo $yzm_session;

}

html代码:

复制代码 代码如下:

<dl>

<dt>验证码:</dt>

<dd>

<input type="text" name="verify_text" value="">

<img src="/user/verify_image" alt="验证码" />

<a href="javascript:changeCode();" >换一张</a>

</dd>

<dd ><b>验证码不正确</b></dd>

<dd ></dd>

</dl>

js代码:

复制代码 代码如下:

<script type="text/javascript">

function changeCode(){

FS.query("#verify_code").src ="/user/verify_image?r=" + Math.random();

}

</script>