php验证码

<?php// header('Location: http://www.baidu.com/');// exit();$image=imagecreatetruecolor(100, 30); //生成一张图$bkcolor=imagecolorallocate($image, 255, 255, 255);//设置图的北京颜色imagefill($image, 0, 0, $bkcolor);//填充图// for($i=0;$i<4;$i++){验证码是数字// $fontSize=8;// $fontColor=imagecolorallocate($image, rand(0, 120), rand(0, 120), rand(0, 120));// $fontContent=rand(0, 9);// $x=($i*25)+rand(5, 10);// $y=rand(5, 10);// imagestring($image, $fontSize, $x, $y, $fontContent, $fontColor);// }for($i=0;$i<4;$i++){//验证码是数字和字母混合$fontSize=6;$fontColor=imagecolorallocate($image, rand(0, 120), rand(0, 120), rand(0, 120));$data='abcdefghijklmnopqrstuvwxyz0123456789';$fontContent=substr($data, rand(0, strlen($data)),1);$x=($i*25)+rand(5, 10); $y=rand(5, 10);imagestring($image, $fontSize, $x, $y, $fontContent, $fontColor);}for($i=0;$i<300;$i++){//添加干扰点$pointClolor=imagecolorallocate($image, rand(50,200), rand(50, 200), rand(50, 200));imagesetpixel($image, rand(1,99), rand(1, 29), $pointClolor);}for($i=0;$i<3;$i++){//添加干扰线$lineColor=imagecolorallocate($image, rand(80, 220), rand(80, 220), rand(80, 220));imageline($image, rand(1, 99), rand(1, 29), rand(1, 99), rand(1, 9), $lineColor);}header('content-type:image/png');imagepng($image);imagedestroy();