twitter通过oAuth验证获取json数据

 protected void Page_Load(object sender, EventArgs e)
        {
            var oAuthConsumerKey = "你的key";
            var oAuthConsumerSecret = "你的secret";
            var oAuthUrl = "https://api.twitter.com/oauth2/token";//授权地址
            var screenname = "查询关键字";
            var authHeaderFormat = "Basic {0}";
            var authHeader = string.Format(authHeaderFormat,
                Convert.ToBase64String(Encoding.UTF8.GetBytes(Uri.EscapeDataString(oAuthConsumerKey) + ":" +
                Uri.EscapeDataString((oAuthConsumerSecret)))
            ));

            var postBody = "grant_type=client_credentials";

            HttpWebRequest authRequest = (HttpWebRequest)WebRequest.Create(oAuthUrl);
            authRequest.Headers.Add("Authorization", authHeader);
            authRequest.Method = "POST";
            authRequest.ContentType = "application/x-www-form-urlencoded;charset=UTF-8";
            authRequest.AutomaticDecompression = DecompressionMethods.GZip | DecompressionMethods.Deflate;

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

            authRequest.Headers.Add("Accept-Encoding", "gzip");

            WebResponse authResponse = authRequest.GetResponse();
            TwitAuthenticateResponse twitAuthResponse;
            using (authResponse)
            {
                using (var reader = new StreamReader(authResponse.GetResponseStream()))
                {
                    JavaScriptSerializer js = new JavaScriptSerializer();
                    var objectText = reader.ReadToEnd();
                    twitAuthResponse = JsonConvert.DeserializeObject<TwitAuthenticateResponse>(objectText);
                }
            }

            var timelineFormat = "https://api.twitter.com/1.1/statuses/user_timeline.json?screen_name={0}&include_rts=1&exclude_replies=1&count=5";
            var timelineUrl = string.Format(timelineFormat, screenname);
            HttpWebRequest timeLineRequest = (HttpWebRequest)WebRequest.Create(timelineUrl);
            var timelineHeaderFormat = "{0} {1}";
            timeLineRequest.Headers.Add("Authorization", string.Format(timelineHeaderFormat, twitAuthResponse.token_type, twitAuthResponse.access_token));
            timeLineRequest.Method = "Get";
            WebResponse timeLineResponse = timeLineRequest.GetResponse();
            var timeLineJson = string.Empty;
            using (timeLineResponse)
            {
                using (var reader = new StreamReader(timeLineResponse.GetResponseStream()))
                {
                    timeLineJson = reader.ReadToEnd();
                }
            }
        }

        public class TwitAuthenticateResponse
        {
            public string token_type { get; set; }
            public string access_token { get; set; }
        }