我有App Token我现在做什么我得到例外？

Question

这是代码：

fb = new FacebookClient("access token");
            dynamic parameters = new ExpandoObject();
            parameters.message = "Check out this funny article";
            parameters.link = "http://www.example.com/article.html";
            parameters.picture = "http://www.example.com/article-thumbnail.jpg";
            parameters.name = "Article Title";
            parameters.caption = "Caption for the link";
            parameters.description = "Longer description of the link";
            parameters.actions = new
            {
                name = "View on Zombo",
                link = "http://www.zombo.com",
            };
            parameters.privacy = new
            {
                value = "ALL_FRIENDS",
            };
            parameters.targeting = new
            {
                countries = "US",
                regions = "6,53",
                locales = "6",
            };
            dynamic result = fb.Post("me/feed", parameters);

我一直得到这个例外：

（OAuthException - ＃2500）必须使用活动访问令牌来查询有关当前用户的信息

在线：

dynamic result = fb.Post("me/feed", parameters);

为什么？