function verifyImage($width=78, $height=26, $type=1, $len=4, $sessName='verify', $lines=4, $pixels=30)
{
session_start(); //开启session
$image = imagecreatetruecolor($width, $height); //创建画布
$bg = imagecolorallocate($image, 255, 255, 255); //背景色
imagefilledrectangle($image, 1, 1, $width - 2, $height - 2, $bg); //画布填充
$str = '';
for($i = 0; $i < $len; $i++) //获取验证码
{
switch ($type) {
case 1:
$str .= range(0, 9)[mt_rand(0, count(range(0, 9)) - 1)];
break;
case 1:
$str .= rand(0, 1) ? range(0, 9)[mt_rand(0, count(range(0, 9)) - 1)] : range('a', 'z')[mt_rand(0, count(range('a', 'z')) - 1)];
break;
default:
break;
}
}
$_SESSION[$sessName] = $str; //写入session
$fontfiles = array('msyh.ttf', 'msyhbd.ttf');
for($i = 0; $i < $len; $i++) //画布写入验证码
{
$size = mt_rand(14, 20); //字体规格
$angle = mt_rand(-30, 30); //角度
$x = mt_rand(4, 8) + $i * $size; //x坐标
$y = mt_rand($height - 8, $height - 4); //y坐标
$color = imagecolorallocate($image, mt_rand(20, 180), mt_rand(40, 200), mt_rand(60, 220)); //字体色
$text = substr($str, $i, 1); //字
$fontfile = $fontfiles[mt_rand(0, count($fontfiles) - 1)]; //字体
imagettftext($image, $size, $angle, $x, $y, $color, $fontfile, $text);
}
if($lines) //干扰线
{
for($i = 0; $i < $lines; $i++)
{
$color = imagecolorallocate($image, mt_rand(20, 180), mt_rand(40, 200), mt_rand(60, 220));
imageline($image, mt_rand(0, $width - 1), mt_rand(0, $height - 1), mt_rand(0, $width - 1), mt_rand(0, $height - 1), $color);
}
}
if($pixels) //干扰点
{
for($i = 0; $i < $pixels; $i++)
{
$color = imagecolorallocate($image, mt_rand(20, 180), mt_rand(40, 200), mt_rand(60, 220));
imagesetpixel($image, mt_rand(0, $width - 1), mt_rand(0, $height - 1), $color);
}
}
header('Content-type:image/gif');
imagegif($image);
imagedestroy($image);
}
