效果圖：
復制代碼 代碼如下:
<?php
/**
* vCode(m,n,x,y) m個數字 顯示大小為n 邊寬x 邊高y
* micxp
*jb51.net
*/
session_start();
vCode(4, 15); //4個數字，顯示大小為15
function vCode($num = 4, $size = 20, $width = 0, $height = 0) {
!$width && $width = $num * $size * 4 / 5 + 5;
!$height && $height = $size + 10;
// 去掉了 0 1 O l 等
$str = "23456789abcdefghijkmnpqrstuvwxyzABCDEFGHIJKLMNPQRSTUVW";
$code = '';
for ($i = 0; $i < $num; $i++) {
$code .= $str[mt_rand(0, strlen($str)-1)];
}
// 畫圖像
$im = imagecreatetruecolor($width, $height);
// 定義要用到的顏色
$back_color = imagecolorallocate($im, 235, 236, 237);
$boer_color = imagecolorallocate($im, 118, 151, 199);
$text_color = imagecolorallocate($im, mt_rand(0, 200), mt_rand(0, 120), mt_rand(0, 120));
// 畫背景
imagefilledrectangle($im, 0, 0, $width, $height, $back_color);
// 畫邊框
imagerectangle($im, 0, 0, $width-1, $height-1, $boer_color);
// 畫干擾線
for($i = 0;$i < 5;$i++) {
$font_color = imagecolorallocate($im, mt_rand(0, 255), mt_rand(0, 255), mt_rand(0, 255));
imagearc($im, mt_rand(- $width, $width), mt_rand(- $height, $height), mt_rand(30, $width * 2), mt_rand(20, $height * 2), mt_rand(0, 360), mt_rand(0, 360), $font_color);
}
// 畫干擾點
for($i = 0;$i < 50;$i++) {
$font_color = imagecolorallocate($im, mt_rand(0, 255), mt_rand(0, 255), mt_rand(0, 255));
imagesetpixel($im, mt_rand(0, $width), mt_rand(0, $height), $font_color);
}
// 畫驗證碼
@imagefttext($im, $size , 0, 5, $size + 3, $text_color, 'c:\\WINDOWS\\Fonts\\simsun.ttc', $code);
$_SESSION["VerifyCode"]=$code;
header("Cache-Control: max-age=1, s-maxage=1, no-cache, must-revalidate");
header("Content-type: image/png;charset=gb2312");
imagepng($im);
imagedestroy($im);
}
?>
