复制代码 代码如下:

<?php

session_start();

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

class SecurityCode

{

private $codes = '';

function __construct()

{

$code = '0-1-2-3-4-5-6-7-8-9-A-B-C-D-E-F-G-H-I-J-K-L-M-N-O-P-Q-R-S-T-U-V-W-X-Y-Z';

$codeArray = explode('-',$code);

shuffle($codeArray);

$this->codes = implode('',array_slice($codeArray,0,4));

}

public function CreateImg()

{

$_SESSION['check_pic'] = $this->codes;

$img = imagecreate(70,25);

imagecolorallocate($img,222,222,222);

$testcolor1 = imagecolorallocate($img,255,0,0);

$testcolor2 = imagecolorallocate($img,51,51,51);

$testcolor3 = imagecolorallocate($img,0,0,255);

$testcolor4 = imagecolorallocate($img,255,0,255);

for ($i = 0; $i < 4; $i++)

{

imagestring($img,rand(5,6),8 + $i * 15,rand(2,8),$this->codes[$i],rand(1,4));

}

imagegif($img);

}

}

$code = new SecurityCode();

$code->CreateImg();

$code = NULL;

?>

封装成类之后，加入了构造函数，使用起来也方便些。你也可以继续完善下这个验证码类，比如加入析构函数，如何更节省内存等等。