Answer 1

Answer 2

如果$facebook->api_client不是对象，则行：

 $facebook->api_client->session_key = FB_SESSION;

将使php静默地将$facebook->api_client强制转换为stdClass类型的对象。其后，在代码之后，将导致您获得的Fatal error: Call to undefined method stdClass::stream_publish()。

尝试更改：      ...

 $facebook = new Facebook(FB_APIKEY, FB_SECRET);
 $facebook->api_client->session_key = FB_SESSION;
 $facebook->api_client->expires = 0;

 ...

在api_client为false（或者可能不是对象）时捕获：

 ...

 $facebook = new Facebook(FB_APIKEY, FB_SECRET);

 if (!( $facebook->api_client )) {
   //throw error 
   echo 'Need to sort this bit out';
   exit;
 }   

 $facebook->api_client->session_key = FB_SESSION;
 $facebook->api_client->expires = 0;

 ...

然后，如果确实发生错误，您需要调查$facebook->api_client为空的原因。