Check if user is following on Twitter using twitter API 1.1

Question

var postData = "source_screen_name=" + source_screen_name + "&target_screen_name=" + target_screen_name;

var updateStatusURL = "https://api.twitter.com/1.1/friendships/show.json" ;

// oauth implementation details

var oauth_version = "1.0";

var oauth_signature_method = "HMAC-SHA1";

// unique request details

var oauth_nonce = Convert.ToBase64String(new ASCIIEncoding().GetBytes(DateTime.Now.Ticks.ToString()));

var timeSpan = DateTime.UtcNow- new DateTime(1970, 1, 1, 0, 0, 0, 0, DateTimeKind.Utc);

var oauth_timestamp = Convert.ToInt64(timeSpan.TotalSeconds).ToString();

// create oauth signature

var baseFormat = "oauth_consumer_key={0}&oauth_nonce={1}&oauth_signature_method={2}" +

"&oauth_timestamp={3}&oauth_token={4}&oauth_version={5}&oauth_callback={6}";

var baseString = string.Format(baseFormat,

oauth_consumer_key,

oauth_nonce,

oauth_signature_method,

oauth_timestamp,

oauth_token,

oauth_version,

Uri.EscapeDataString(strcallbackurl)

);

baseString = string.Concat("GET&", Uri.EscapeDataString(updateStatusURL), "&", Uri.EscapeDataString(baseString));

var compositeKey = string.Concat(Uri.EscapeDataString(oauth_consumer_secret),

"&", Uri.EscapeDataString(oauth_verifier));

string oauth_signature;

using (HMACSHA1 hasher = new HMACSHA1(ASCIIEncoding.ASCII.GetBytes(compositeKey)))

{

oauth_signature = Convert.ToBase64String(

hasher.ComputeHash(ASCIIEncoding.ASCII.GetBytes(baseString)));

}

// create the request header

var headerFormat = "OAuth oauth_nonce=\"{0}\", oauth_signature_method=\"{1}\", " +

"oauth_timestamp=\"{2}\", oauth_consumer_key=\"{3}\", " +

"oauth_token=\"{4}\", oauth_signature=\"{5}\", " +

"oauth_version=\"{6}\"";

var authHeader = string.Format(headerFormat,

Uri.EscapeDataString(oauth_nonce),

Uri.EscapeDataString(oauth_signature_method),

Uri.EscapeDataString(oauth_timestamp),

Uri.EscapeDataString(oauth_consumer_key),

Uri.EscapeDataString(oauth_token),

Uri.EscapeDataString(oauth_signature),

Uri.EscapeDataString(oauth_version)

);

ServicePointManager.Expect100Continue = false;

//var postBody = "q=" + Uri.EscapeDataString(q);//

updateStatusURL += "?" + postData;

HttpWebRequest request = (HttpWebRequest)WebRequest.Create(updateStatusURL);

request.Headers.Add("Authorization", authHeader);

request.Method = "GET";

request.ContentType = "application/x-www-form-urlencoded";

var response = (HttpWebResponse)request.GetResponse();

var reader = new StreamReader(response.GetResponseStream());

var objText = reader.ReadToEnd();

return request;

 

 I want to check whether if a user is following you on Twitter using twitter API 1.1 but I am getting an error while getting the response

The remote server returned an error: (401) Unauthorized.

Am I doingsomething wrong?