具体内容如下

valid();
$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)){

        $postObj = simplexml_load_string($postStr, 'SimpleXMLElement', LIBXML_NOCDATA);
        $fromUsername = $postObj->FromUserName;
        $toUsername = $postObj->ToUserName;
        $type = $postObj->MsgType;
        $customrevent = $postObj->Event;
        $latitude = $postObj->Location_X;
        $longitude = $postObj->Location_Y;
        $keyword = trim($postObj->Content);
        $time = time();
        $textTpl = "
              
              
              %s
              
              
              0
              ";       
        switch ($type)
      {  case "event";
        if ($customrevent=="subscribe")
          {$contentStr = '';}
        break;
        case "image";
        $contentStr = "你的图片很棒！";
        break;
        case "location";
        $disurl="http://maps.googleapis.com/maps/api/distancematrix/xml?origins={$latitude},{$longitude}&destinations=23.355164,116.681889&mode=walking&language=zh-CN&sensor=false";
      $apistr=file_get_contents($disurl);
      $apiobj=simplexml_load_string($apistr);
      $disobj=$apiobj->row->element->distance->text;
      $durobj=$apiobj->row->element->duration->text;
      $contentStr = "你离我公司约{$disobj}公里，步行约{$durobj}";

        break;
        case "link" ;
        $contentStr = "你的链接有病毒吧！";
        break;
        case "text";
        $weatherurl="http://api.map.baidu.com/telematics/v2/weather?location={$keyword}&ak=1a3cde429f38434f1811a75e1a90310c";
         $apistr=file_get_contents($weatherurl);
         $apiobj=simplexml_load_string($apistr);
         $placeobj=$apiobj->currentCity;//读取城市
         $todayobj=$apiobj->results->result[0]->date;//读取星期
         $weatherobj=$apiobj->results->result[0]->weather;//读取天气
         $windobj=$apiobj->results->result[0]->wind;//读取风力
         $temobj=$apiobj->results->result[0]->temperature;//读取温度
         $contentStr = "{$placeobj}{$todayobj}天气{$weatherobj}，风力{$windobj}，温度{$temobj}";
         break;          
      default;
      $contentStr ="此项功能尚未开发";  
      }
        $msgType="text";
        $resultStr = sprintf($textTpl, $fromUsername, $toUsername, $time, $msgType, $contentStr);
        echo $resultStr;


    }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;
    }
  }
}

?>