如何让Facebook喜欢只计入Facebook页面？

Question

我必须得到Facebook喜欢的特定页面，

我已经完成了

How to get Facebook likes count for a Facebook page?，但是在此之后，accesstoken将在某种程度上过期，并尝试重新生成如下所示的accesstoken：

    public static string RefreshAccessToken(string currentAccessToken)
    {
        var client = new WebClient();       
        FacebookClient fbClient = new FacebookClient();
        Dictionary<string, object> fbParams = new Dictionary<string, object>();          
        fbParams["client_id"] = "xxxxxxxxxxxxxxx";
        fbParams["grant_type"] = "fb_exchange_token";
        fbParams["client_secret"] = "xxxxxxxxxxxxxxx";
        fbParams["fb_exchange_token"] = currentAccessToken;
        JsonObject publishedResponse = fbClient.Get("/oauth/access_token", fbParams) as JsonObject;
        string newaccesstoken = publishedResponse["access_token"].ToString();           
        return newaccesstoken;
    }

它也失败了，你能不能告诉我如何在没有永不过期的访问权限的情况下获得计数？