它作为signed_request的一部分传递给您的应用程序，它被称为页面：

it is passed as a part of a signed_request to your app, it is called "page":

页面id字符串，如果
用户喜欢该页面，则喜欢的布尔值，如果用户是管理员，则为布尔值。
仅当您的应用程序是在页面选项卡中加载的iframe时才可用。

A JSON object containing the page id string, the liked boolean if the user has liked the page, the admin boolean if the user is an admin. Only available if your app is an iframe loaded in a Page tab.

https://developers.facebook.com/docs/authentication/signed_request/