一步一步教你做php生成验证码程序代码

一步一步教你做php生成验证码程序代码

代码如下:

<?php

session_start();

$enablegd = 1;

//判断图像处理函数是否存在

$funcs = array('imagecreatetruecolor','imagecolorallocate','imagefill','imagestring','imageline','imagerotate','imagedestroy','imagecolorallocatealpha','imageellips教程e','imagepng');

foreach($funcs as $func)

{

if(!function_exists($func))

{

$enablegd = 0;

break;

}

}

ob_clean(); //清理缓冲

if($enablegd)

{

//create captcha

$consts = 'cdfgkmnpqrstwxyz23456';

$vowels = 'aek23456789';

for ($x = 0; $x < 6; $x++)

{

$const[$x] = substr($consts, mt_rand(0,strlen($consts)-1),1); //获取$consts中的一个随机数

$vow[$x] = substr($vowels, mt_rand(0,strlen($vowels)-1),1); //获取$vowels中的一个随机数

}

$radomstring = $const[0] . $vow[0] .$const[2] . $const[1] . $vow[1] . $const[3] . $vow[3] . $const[4];

$_SESSION['checkcode'] = $string = substr($radomstring,0,4); //显示4个字符

$imageX = strlen($radomstring)*8; //图像的宽

$imageY = 20; //图像的高

$im = imagecreatetruecolor($imageX,$imageY); //新建一个真彩色图像

//creates two variables to store color

$background = imagecolorallocate($im, rand(180, 250), rand(180, 250), rand(180, 250)); //背景色

$foregroundArr = array(imagecolorallocate($im, rand(0, 20), rand(0, 20), rand(0, 20)),

imagecolorallocate($im, rand(0, 20), rand(0, 10), rand(245, 255)),

imagecolorallocate($im, rand(245, 255), rand(0, 20), rand(0, 10)),

imagecolorallocate($im, rand(245, 255), rand(0, 20), rand(245, 255))

);

$foreground2 = imagecolorallocatealpha($im, rand(20, 100), rand(20, 100), rand(20, 100),80); //分配颜色并说明透明度

$middleground = imagecolorallocate($im, rand(200, 160), rand(200, 160), rand(200, 160)); //中间背景

$middleground2 = imagecolorallocatealpha($im, rand(180, 140), rand(180, 140), rand(180, 140),80); //中间背景2

//与左上角的颜色相同的都会被填充

imagefill($im, 0, 0, imagecolorallocate($im, 250, 253, 254));

//往图像上写入文字

imagettftext($im, 12, rand(30, -30), 5, rand(14, 16), $foregroundArr[rand(0,3)], 'C:WindowsFontsArial.ttf', $string[0]);

imagettftext($im, 12, rand(50, -50), 20, rand(14, 16), $foregroundArr[rand(0,3)], 'C:WindowsFontsArial.ttf', $string[1]);

imagettftext($im, 12, rand(50, -50), 35, rand(14, 16), $foregroundArr[rand(0,3)],'C:WindowsFontsArial.ttf', $string[2]);

imagettftext($im, 12, rand(30, -30), 50, rand(14, 16), $foregroundArr[rand(0,3)],'C:WindowsFontsArial.ttf', $string[3]);

//画边框

$border = imagecolorallocate($im, 133, 153, 193);

imagerectangle($im, 0, 0, $imageX - 1, $imageY - 1, $border);

//画一些随机出现的点

$pointcol = imagecolorallocate($im, rand(0,255), rand(0,255), rand(0,255));

for ($i=0;$i<80;$i++)

{

imagesetpixel($im,rand(2,$imageX-2),rand(2,$imageX-2),$pointcol);

}

//画随机出现的线

for ($x=0; $x<9;$x++)

{

if(mt_rand(0,$x)%2==0)

{

imageline($im, rand(0, 120), rand(0, 120), rand(0, 120), rand(0, 120), rand(0, 999999)); //画线

imageellipse($im, rand(0, 120), rand(0, 120), rand(0, 120), rand(0, 120), $middleground2); //画椭圆

}

else

{

imageline($im, rand(0, 120), rand(0, 120), rand(0, 120), rand(0, 120), rand(0, 999999));

imageellipse($im, rand(0, 120), rand(0, 120), rand(0, 120), rand(0, 120), $middleground);

}

}

//output to browser

header("content-type:image/pngrn");

imagepng($im);

imagedestroy($im);

}

else

{

$files = glob(XINCHENG_ROOT.'images/checkcode/*.jpg');
if(!is_array($files)) die('请检查文件目录完整性:/images/checkcode/');

$checkcodefile = $files[rand(0, count($files)-1)]; //随机其中一个文件

$_SESSION['checkcode'] = substr(basename($checkcodefile), 0, 4); //获得文件名

header("content-type:image/jpegrn");

include $checkcodefile;

}

?>