微信开发返回验证来源方式代码

<?php
$xml = simplexml_load_string($GLOBALS['HTTP_RAW_POST_DATA']);
$arr = array(
    'appid'=> (string)$xml->AppId,
    'appkey'=>$appkey,
    'issubscribe'=> (string)$xml->IsSubscribe,
    'noncestr'=> (string)$xml->NonceStr,
    'openid'=> (string)$xml->OpenId,
    'timestamp'=> (string)$xml->TimeStamp
);

$sign = sha1( http_build_query($arr) );
if( $sign == $xml->AppSignature){
 echo "success";
}

?>