<?php  
/** 
* wechat php test 
*/  
//define your token  
define("TOKEN", "weixin");//此时你的微信公众平台的token即为weixin  
$wechatObj = new wechatCallbackapiTest();  
$wechatObj->valid();  
class wechatCallbackapiTest  
{  
public function valid()  
{  
$echoStr = $_GET["echostr"];  
//valid signature , option  
if($this->checkSignature()){  
echo $echoStr;  
exit;  
}  
}  
public function responseMsg()  
{  
//get post data, May be due to the different environments  
$postStr = $GLOBALS["HTTP_RAW_POST_DATA"];  
//extract post data  
if (!empty($postStr)){  
$postObj = simplexml_load_string($postStr, 'SimpleXMLElement', LIBXML_NOCDATA);  
$fromUsername = $postObj->FromUserName;  
$toUsername = $postObj->ToUserName;  
$keyword = trim($postObj->Content);  
$time = time();  
$textTpl = "<xml>  
<ToUserName><![CDATA[%s]]></ToUserName>  
<FromUserName><![CDATA[%s]]></FromUserName>  
<CreateTime>%s</CreateTime>  
<MsgType><![CDATA[%s]]></MsgType>  
<Content><![CDATA[%s]]></Content>  
<FuncFlag>0</FuncFlag>  
</xml>";  
if(!empty( $keyword ))  
{  
$msgType = "text"; （PS：^_^不错的php学习交流群：276167802，验证：csl，有兴趣的话可以加入进来一起讨论）  
$contentStr = "Welcome to wechat world!";  
$resultStr = sprintf($textTpl, $fromUsername, $toUsername, $time, $msgType, $contentStr);  
echo $resultStr;  
}else{  
echo "Input something...";  
}  
}else {  
echo "";  
exit;  
}  
}  
private function checkSignature()  
{  
$signature = $_GET["signature"];  
$timestamp = $_GET["timestamp"];  
$nonce = $_GET["nonce"];  
$token = TOKEN;  
$tmpArr = array($token, $timestamp, $nonce);  
sort($tmpArr);  
$tmpStr = implode( $tmpArr );  
$tmpStr = sha1( $tmpStr );  
if( $tmpStr == $signature ){  
return true;  
}else{  
return false;  
}  
}  
}  
?>