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)];
}
// 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, $text_color, 'c://WINDOWS//Fonts//simsun.ttc',$code);
header("Cache-Control: max-age=1, s-maxage=1, no-cache, must-revalidate");
header("Content-type: image/png");
imagepng($im);
imagedestroy($im);
}
?>
函数描述及例子:
// 4个字符,大小为20
vCode(4,20);
?>
