例子,调用google接口来实现二维码。
 
<?php 
$data = isset($_GET['t']) ? $_GET['t'] : 'http://www.XXX.com'; 
$size = isset($_GET['size']) ? $_GET['size'] : '150x150'; 
$logo = isset($_GET['logo']) ? $_GET['logo'] :"./image/logo.jpg "/>";
$chl = urlencode($logo); 
$png = "http://chart.googleapis.com/chart?chs=$size&cht=qr&chl=$chl&chld=L|1&choe=UTF-8"; 
$QR = imagecreatefrompng($png);//外面那QR图
//以下是二维码生成的主要代码
if ($logo !== FALSE) { 
$logo = imagecreatefromstring(file_get_contents($logo)); 
$QR_width = imagesx($QR); 
$QR_height = imagesy($QR); 
$logo_width = imagesx($logo); 
$logo_height = imagesy($logo); 
$logo_qr_width = $QR_width/5; 
$scale = $logo_width/$logo_qr_width; 
$logo_qr_height = $logo_height/$scale; 
$from_width = ($QR_width-$logo_qr_width)/2; 
imagecopyresampled($QR, $logo, $from_width, $from_width, 0, 0, $logo_qr_width, $logo_qr_height, $logo_width, $logo_height); 
}
header('Content-type: image/png'); 
imagepng($QR);
//销毁二维码图像
imagedestroy($QR); 
?>