Facebook.FacebookOAuthClient.GetApplicationAccessTokenAsync C# (CSharp) Method

        public void GetApplicationAccessTokenAsync(IDictionary<string, object> parameters, object userToken)
        {
            string name, path;

            var pars = BuildApplicationAccessTokenParameters(parameters, out name, out path);

            OAuthRequestAsync(
                name, path, pars, userToken,
                json => BuildApplicationAccessTokenResult(json).ToString(),
                (o, e) =>
                {
                    if (GetApplicationAccessTokenCompleted != null)
                    {
                        GetApplicationAccessTokenCompleted(this, e);
                    }
                });
        }

        /// <summary>
        /// Gets the application access token asynchronously.
        /// </summary>
        /// <param name="facebookOAuthClient">The Facebook OAuth Client.</param>
        /// <param name="parameters">The parameters.</param>
        /// <returns>The task of the result.</returns>
        public static Task <object> GetApplicationAccessTokenTaskAsync(this FacebookOAuthClient facebookOAuthClient, IDictionary <string, object> parameters)
        {
            var tcs = FacebookClientTaskExtensions.CreateSource <object>(null);

            EventHandler <FacebookApiEventArgs> handler = null;

            handler = (sender, e) => FacebookClientTaskExtensions.TransferCompletionToTask <object>(tcs, e, () => e.GetResultData(), () => facebookOAuthClient.GetApplicationAccessTokenCompleted -= handler);

            facebookOAuthClient.GetApplicationAccessTokenCompleted += handler;

            try
            {
                facebookOAuthClient.GetApplicationAccessTokenAsync(parameters, tcs);
            }
            catch
            {
                facebookOAuthClient.GetApplicationAccessTokenCompleted -= handler;
                tcs.TrySetCanceled();
                throw;
            }

            return(tcs.Task);
        }