这是一个如何做到这一点的例子 – 使用

gd function调用来制作你的图像,但是玩得很好并缓存图像.这个示例通过确保如果浏览器已经具有所需图像,则返回304 …

#here's where we'll store the cached images

$cachedir=$_SERVER['DOCUMENT_ROOT'].'/imgcache/'

#get the score and sanitize it

$score=$_GET['score'];

if (preg_match('/^[0-9]\.[0-9]{1,2}$/', $score)

{

#figure out filename of cached file

$file=$cachedir.'score'.$score.'gif';

#regenerate cached image

if (!file_exists($file))

{

#generate image - this is lifted straight from the php

#manual, you'll need to work out how to make your

#image, but this will get you started

#load a background image

$im = imagecreatefrompng("images/button1.png");

#allocate color for the text

$orange = imagecolorallocate($im, 220, 210, 60);

#attempt to centralise the text

$px = (imagesx($im) - 7.5 * strlen($score)) / 2;

imagestring($im, 3, $px, 9, $score, $orange);

#save to cache

imagegif($im, $file);

imagedestroy($im);

}

#return image to browser, but return a 304 if they already have it

$mtime=filemtime($file);

$headers = apache_request_headers();

if (isset($headers['If-Modified-Since']) &&

(strtotime($headers['If-Modified-Since']) >= $mtime))

{

// Client's cache IS current, so we just respond '304 Not Modified'.

header('Last-Modified: '.gmdate('D, d M Y H:i:s', $mtime).' GMT', true, 304);

exit;

}

header('Content-Type:image/gif');

header('Content-Length: '.filesize($file));

header('Last-Modified: '.gmdate('D, d M Y H:i:s', $mtime).' GMT');

readfile($file);

}

else

{

header("HTTP/1.0 401 Invalid score requested");

}

如果你将它放在image.php中,你将在图像标记中使用如下