微信公众平台开发关注/取消关注事件例子

define("TOKEN", "w3note");//定义识别码
$wechatObj = new wechatCallbackapiTest();//实例化wechatCallbackapiTest类

if(!isset($_GET["echostr"])){
     $wechatObj->responseMsg();
}else{
 $wechatObj->valid();
}
class wechatCallbackapiTest
{
 public function valid()
    {
        $echoStr = $_GET["echostr"];
      
        if($this->checkSignature()){
         echo $echoStr;
         exit;
        }
    }
    public function responseMsg()//执行接收器方法
    {

  $postStr = $GLOBALS["HTTP_RAW_POST_DATA"];

  if (!empty($postStr)){
              
               $postObj = simplexml_load_string($postStr, 'SimpleXMLElement', LIBXML_NOCDATA);
      $RX_TYPE = trim($postObj->MsgType);
      switch($RX_TYPE){
       case "event":
       $result = $this->receiveEvent($postObj);
       breadk;
      }
      echo $result;
  }else{
   echo "";
   exit;
  }
 }
  private function receiveEvent($object){
   $content = "";
   switch ($postObj->Event){
    case "subscribe":
    $content = "欢迎关注网志博客";//这里是向关注者发送的提示信息
    break;
    case "unsubscribe":
    $content = "";
    break;
   }
   $result = $this->transmitText($object,$content);
   return $result;
 
    }
 private function transmitText($object,$content){
   $textTpl = "
      
      
       %s
      
      
       0
       ";
    $result = sprintf($textTpl, $object->FromUserName, $object->$ToUserName, time(), $content);
    return $result;
 
  }
 private function checkSignature()
 {
        $signature = $_GET["signature"];
        $timestamp = $_GET["timestamp"];
        $nonce = $_GET["nonce"];
        
  $token = TOKEN;
  $tmpArr = array($token, $timestamp, $nonce);
  sort($tmpArr, SORT_STRING);
  $tmpStr = implode( $tmpArr );
  $tmpStr = sha1( $tmpStr );
 
  if( $tmpStr == $signature ){
   return true;
  }else{
   return false;
  }
 }
}