create_code.php <?php session_start(); //生成验证码图片 header("Content-type: image/png"); // 全数字 $str = "1,2,3,4,5,6,7,8,9,a,b,c,d,f,g"; //要显示的字符,可自己进行增删 $list = explode(",", $str); $cmax = count($list) - 1; $verifyCode = ‘‘; for ( $i=0; $i < 5; $i++ ){ $randnum = mt_rand(0, $cmax); $verifyCode .= $list[$randnum]; //取出字符,组合成为我们要的验证码字符 } $_SESSION[‘code‘] = $verifyCode; //将字符放入SESSION中 $im = imagecreate(58,28); //生成图片 $black = imagecolorallocate($im, 0,0,0); //此条及以下三条为设置的颜色 $white = imagecolorallocate($im, 255,255,255); $gray = imagecolorallocate($im, 200,200,200); $red = imagecolorallocate($im, 255, 0, 0); imagefill($im,0,0,$white); //给图片填充颜色 //将验证码绘入图片 imagestring($im, 5, 10, 8, $verifyCode, $black); //将验证码写入到图片中 for($i=0;$i<50;$i++) //加入干扰象素 { imagesetpixel($im, rand()p , rand()0 , $black); //加入点状干扰素 imagesetpixel($im, rand()p , rand()0 , $red); imagesetpixel($im, rand()p , rand()0 , $gray); //imagearc($im, rand()p, rand()p, 20, 20, 75, 170, $black); //加入弧线状干扰素 //imageline($im, rand()p, rand()p, rand()p, rand()p, $red); //加入线条状干扰素 } imagepng($im); imagedestroy($im); ?>
PHP中最简单的验证码
时间: 2024-10-09 23:52:16