How do I convert from an app token to a page token using the Facebook graph API?
<p>I'm using the Facebook .NET SDK.</p>

<p>I can generate an app access like so:</p>

<pre><code>var client = new FacebookClient();
dynamic appAccessToken =
            client.Get(
                string.Format("/oauth/access_token?client_id={0}&amp;client_secret={1}&amp;grant_type=client_credentials", appId, appSecret));
</code></pre>

<p>which brings me back an access token in the format <code>{appId}|{token}</code></p>

<p>If I then pass this back into the client object I hoped to get a page access token, but I'm just getting back the page Id, where I as expecting to get the page Id and an access token.</p>

<p>Full code:</p>

<pre><code>var client = new FacebookClient();
dynamic appAccessToken =
            client.Get(
                string.Format("/oauth/access_token?client_id={0}&amp;client_secret={1}&amp;grant_type=client_credentials", appId, appSecret));
client.AccessToken = appAccessToken.access_token;
dynamic tokens = client.Get(string.Format("/v2.5/{0}?fields=access_token", pageId));
</code></pre>