如何使用REST API从我的ASP.NET应用程序更新Facebook上的状态？

Question

//这是我的代码。我在asp.net C＃页面上写过。请检查一下，并告诉我哪里出错......以及为什么它不起作用????

                          using System;
                         using System.Collections.Generic;
                         using System.Linq;
                         using System.Web;
                         using System.Web.UI; 
                         using System.Web.UI.WebControls;
                         using System.Net;
                         using System.IO;
                         using System.Text;
                         using System.Security.Cryptography;

           public partial class _Default : System.Web.UI.Page
           {
             protected void Page_Load(object sender, EventArgs e)
            {
          updatefbstatus();
       Label1.Text = "You have successfully updated your status";
             }
        public void updatefbstatus()
               {
        string app_id = "4674344535438035667565358488";
        string app_secret = "336851d2c3fhg7675g45ts2b89c46e58aa287fbf6kjiu766771f";
        string scope = "publish_stream,manage_pages";


       string status = "hello billu";

       if (Request["code"] == null)
       {
          Response.Redirect(string.Format(
              "https://graph.facebook.com/oauth/authorize?client_id={0}&redirect_uri=      
               {1}&scope={2}",
            app_id, Request.Url.AbsoluteUri, scope));

         }
       else
       {
           Dictionary<string, string> tokens = new Dictionary<string, string>();

        string url = string.Format("https://graph.facebook.com/oauth/access_token?  
           client_id={0}&redirect_uri={1}&scope={2}&code={3}&client_secret={4}&status= 
         {5}",
            app_id, Request.Url.AbsoluteUri, scope, Request["code"].ToString(),  
            app_secret, status);
        tokens.Add("message", status);
        var auth = Uri.EscapeDataString(url) + Uri.EscapeDataString(status);
        var postBody = "status=" + Uri.EscapeDataString(status);


        HttpWebRequest request = WebRequest.Create(url) as HttpWebRequest;
        request.Headers.Add("Authorization", auth);
        request.Method = "POST";

        request.ContentType = "application/json";

        using (Stream stream = request.GetRequestStream())
        {
            byte[] content = ASCIIEncoding.ASCII.GetBytes(postBody);
            stream.Write(content, 0, content.Length);
        }

        WebResponse rsp = request.GetResponse() as HttpWebResponse;
        Stream dataStream = rsp.GetResponseStream();
        StreamReader reader = new StreamReader(dataStream);
        string responseFromServer = reader.ReadToEnd();

                 }
             }
          }