A piece of code for php to generate dynamic image verification code-PHP Tutorial-php.cn

A piece of code for php to generate dynamic image verification code

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Release： 2016-07-25 09:03:16

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session_start();
function random($len)
{
$srCStr="ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789";
$strs="";
for($i=0;$i<$ len;$i++)
{
$strs.=$srCStr[mt_rand(0,35)];
}
return $strs;
}
$str=random(4); //Randomly generated string
$ width = 50; //The width of the verification code image
$height = 25; //The height of the verification code image
@header("Content-Type:image/png");
$_SESSION["code"] = $str ;
$im = imagecreate($width,$height);
//Background color
$back = imagecolorallocate($im,0xFF,0xFF,0xFF);
//Blurry point color
$pix = imagecolorallocate($im, 187,230,247);
//Font color
$font = imagecolorallocate($im,41,163,238);
//Points for blurring
for($i=0;$i<1000;$i++)
{
imagesetpixel($ im,mt_rand(0,$width),mt_rand(0,$height),$pix);
}
imagestring($im, 5, 7, 5,$str, $font);
imagerectangle($im,0 ,0,$width-1,$height-1,$font);
imagepng($im);
imagedestroy($im);
$_SESSION["code"] = $str;
?>

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