private async Task<OAuth> SignInAsyncTask(string username, string password) { var o = new OAuth(ConsumerKey, ConsumerSecret); var uri = new Uri(XAuthUrl); string xauth = string.Format("x_auth_mode=client_auth&x_auth_password={0}&x_auth_username={1}", password.UrlEncode(), username.UrlEncode()); uri = o.SignUri(uri, extraSignature: xauth, httpmethod: "POST"); string result = await uri.HttpPost(xauth); if (result == null) return null; string token = ""; string tokensecret = ""; foreach (var val in result.Split('&').Select(item => item.Split('='))) { switch (val[0]) { case "oauth_token": token = val[1]; break; case "oauth_token_secret": tokensecret = val[1]; break; } } o.Token = token; o.TokenSecret = tokensecret; return o; }