php配置微信平台接口遇到的问题 ： 配置报错 

服务器配置已经OK，然后将$wechatObj->valid()  修改成 $wechatObj->responseMsg() ！
在微信里给公众账号发信息没有信息返回？不知道为什么？

define("TOKEN", "weixin"); $wechatObj = new wechatCallbackapiTest(); $wechatObj->responseMsg();

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)){
            /* libxml_disable_entity_loader is to prevent XML eXternal Entity Injection,
               the best way is to check the validity of xml by yourself */
            libxml_disable_entity_loader(true);
          	$postObj = simplexml_load_string($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";
            	$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()
{
    // you must define TOKEN by yourself
    if (!defined("TOKEN")) {
        throw new Exception('TOKEN is not defined!');
    }
    
    $signature = $_GET["signature"];
    $timestamp = $_GET["timestamp"];
    $nonce = $_GET["nonce"];
    		
	$token = TOKEN;
	$tmpArr = array($token, $timestamp, $nonce);
    // use SORT_STRING rule
	sort($tmpArr, SORT_STRING);
	$tmpStr = implode( $tmpArr );
	$tmpStr = sha1( $tmpStr );
	
	if( $tmpStr == $signature ){
		return true;
	}else{
		return false;
	}
}

}