微信公众平台开发，外部调用接口传参，然后把参数以图文形式回复

1. 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();
                  $imgurl  = $_GET['id'];  
                  $textTpl = "
                              
                              
                              %s
                              
                              
                              0
                              ";             
                  $ev = $postObj->Event;
                  if ($ev == "subscribe")
                  {
   
                      $PicUrl = $imgurl;
   
                      $Url    = $imgurl;
   
                      $textTpl = "
                                  
                                  
                                  %s
                                  
                                  1
                                  
                                  
                                   
                                  
                                  
                                  
                                  
                                  
                                  
                                   ";     
   

                  $resultStr = sprintf($textTpl, $fromUsername, $toUsername, $time);
                     echo $resultStr;
                  
                  }
                  
                  
                  
                  if(!empty( $keyword ))
                  {   
   
                        $msgType = "text";
                      switch ($keyword)
                      {
                      case "1";
                      $contentStr = "公司简介!";
                      break;
                      case "2";
                      $contentStr = "最新优惠!";
                      break;
                      case "3";
                      $contentStr = "图片链接如下:".$_GET['id'];
                      break;
                      default;
                      $contentStr = "欢迎光临!";
                                  
                      
                      }
                      
                      $resultStr = sprintf($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;
          }
      }

   }

   ?>

回复内容：

微信公众平台开发，外部调用接口以URL形式传参，然后写用户关注后以图文形式回复，图片的url就是传过来的参数
。但是我微信关注后没有获得参数。

http://xxx.duapp.com/wechat/api.php?id=http://203.111.111.111:1212/img/635932895447623934.png  

代码如下：