12306验证码太难，试着用php自己做一个验证码吧！

<span style="font-family: Verdana, 'Lantinghei SC', 'Hiragino Sans GB', 'Microsoft Yahei', Helvetica, arial, 宋体, sans-serif; line-height: 16.8px; background-color: rgb(255, 255, 255);">今年春运买票的朋友们碰上了12306的新验证码，各种吐槽，各种从一堆相似图片中选择答案。最后果然被网友们玩坏了……</span>

其实验证码很简单，简单说就是一个用xx编程语言处理图片的操作。
大致思路这样的： 定好一个验证码规则，画一些内容到图片上，然后把我们传达给用户的信息放在某个地方（session、db）保存起
来，最终展现给用户。
demo地址： http://demo.cntnn11.com/images/imgcode.php

下边是php代码，注意：请注意字体路径

<?php
session_start();
error_reporting(E_ALL);
/**
*	一个简单的加乘验证码类
*	@author z53
*	@datetime 2016-01-07
*/

class codeimg
{
public $width	= 150;
public $height	= 35;

public $num_1	= 1;
public $num_2	= 10;

public $f_file	= './font/YaHei.Consolas.1.12.ttf';
public $f_size	= 13;

public $c_type	= 1;	//验证码类型：1加乘混合出现/2纯加法/3纯乘法。默认为1
public $imgSourc= '';

public $line	= true;
public $lineNum	= 0;

private $sess	= '';	//存入session的值
private $dev	= FALSE;//调试模式，也就是不输出header("content-type: image/png;");也不生成图片。测试的

function __construct()
{
$this->genImg();
}

function genImg()
{
$this->imgSourc	= $this->createImgSourc();
if(!$this->dev)
{
header("content-type: image/png;");
imagepng($this->imgSourc);
imagedestroy($this->imgSourc);
}
}

function createImgSourc()
{
$this->imgSourc	= imagecreate($this->width, $this->height);
$bgcolor	= imagecolorallocate($this->imgSourc, 255, 255, 255);

//是否生成干扰线
if($this->line)
{
$this->genLine();
}

$text	= $this->genStr();
$strlen	= mb_strlen($text);

$y		= intval(($this->height-$this->f_size));
$x		= intval(($this->height-$strlen));

$textColor	= imagecolorallocate($this->imgSourc, rand(0, 125), rand(0, 125), rand(0, 125));

if( !function_exists('imagettftext'))
{
exit('imagettftext 不存在！');
}
else
{
imagettftext($this->imgSourc, $this->f_size, 0, $x, $y, $textColor, $this->f_file, $text);
}

return $this->imgSourc;
}

/**
*	干扰线线的生成
*	根据$this->lineNum决定生成多少条线，默认为随机生成5~12条
*/
function genLine()
{
$lineNum	= empty($this->lineNum) ? rand(5, 12) : $this->lineNum;
for($i = 1; $i <= $lineNum; $i++ )
{
$linecolor	= imagecolorallocate($this->imgSourc, rand(0 , 255), rand(0, 255), rand(0, 255));
imageline($this->imgSourc, rand(1 , $this->width), rand(1, $this->height), rand(1, $this->width), rand(1, $this->height), $linecolor);
}
}

/**
*	生成图片里的内容
*	@return string
*/
function genStr()
{
$operArr	= array('加', '乘');
$operNum	= $this->c_type === 2 ? 0 : ($this->c_type === 3 ? 1 : rand(0, 1));

$numArr[0]	= rand(intval($this->num_1), intval($this->num_2));
$numArr[1]	= rand(intval($this->num_1), intval($this->num_2));

if($operNum === 1)
{
$numArr[2]	= intval($numArr[0])*intval($numArr[1]);
}
else
{
$numArr[2]	= intval($numArr[0])+intval($numArr[1]);
}

$temp_num	= rand(0, 2);
$this->sess	= $numArr[$temp_num];
$numArr[$temp_num]	= '**';
$string		= $numArr[0].' '.$operArr[$operNum].' '.$numArr[1].' = '.$numArr[2];
return $string;
}

function getValue()
{
return $this->sess;
}

}
header("content-type: text/html; charset=utf-8");
$objimg	= new codeimg();
$_SESSION['scode']	= $objimg->getValue();
?>