/**
* vCode (m,n,x,y) m个数字 显示大小为n 边宽x 边高y
* http://blog.qita.in
* 自己改写记录session $code
*/
session_start ();
vCode (4, 15); //4个数字,显示大小为15
function vCode ($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 = $_GET[ // 画图像
$im = imagecreatetruecolor ($width, $height);
// 定义要用到的颜色
$back_color = imagecolorallocate ($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));
// 画背景
imagefilledrectangle ($im, 0, 0, $width, $height, $back_color);
// 画边框
imagerectangle ($im, 0, 0, $width-1, $height-1, $boer_color);
// 画干扰线
for ($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), $font_color);
}
// 画干扰点
for ($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), $font_color);
}
// 画验证码
@imagefttext ($im, $size , 0, 5, $size + 3, $text_color, $_SESSION["VerifyCode"]=$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);
}
?>