/// <summary>
        /// 请求授权
        /// </summary>
        /// <param name="Code">调用authorize获得的code值。</param>
        /// <returns>AccessTokenInfo</returns>
        public static async Task<AccessTokenInfo> GetAccessToken(string Code)
        {
            string url = "https://api.worktile.com/oauth2/access_token";
            Dictionary<string, string> parameters = new Dictionary<string, string>();
            parameters.Add("client_id", app_key);
            parameters.Add("client_secret", app_secret);
            parameters.Add("code", Code);

            string json = await Helper.HttpHelper.DoPost(url, parameters);
            if (string.IsNullOrEmpty(json))
            {
                return null;
            }
            else
            {
                //开始解析返回数据
                try
                {
                    Debug.WriteLine("开始解析返回json---\n" + json);
                    JObject result = JObject.Parse(json);
                    Debug.WriteLine("解析返回json成功---\n");

                    AccessTokenInfo accessToken = new AccessTokenInfo();
                    accessToken.AccessToken = result["access_token"].ToString();
                    accessToken.RefreshToken = result["refresh_token"].ToString();
                    accessToken.RequestTime = DateTime.Now;
                    int expiresIn = int.Parse(result["expires_in"].ToString());
                    accessToken.ExpiresTime = accessToken.RequestTime.AddSeconds(expiresIn);
                    return accessToken;
                }
                catch (Exception)
                {
                    Debug.WriteLine("解析返回json失败---\n" + json);
                    return null;
                }
            }
        }
        private void SaveAccessToken(AccessTokenInfo AccessToken)
        {
            string[] keys = new string[] { "access_token", "expires_time", "refresh_token" };
            foreach (string key in keys)
            {
                if (!localSetting.Values.ContainsKey(key)) { localSetting.Values.Add(key, ""); };
            }

            localSetting.Values["access_token"] = AccessToken.AccessToken;
            localSetting.Values["refresh_token"] = AccessToken.RefreshToken;
            localSetting.Values["expires_time"] = AccessToken.ExpiresTime.ToString();
            localSetting.Values["request_time"] = AccessToken.RequestTime.ToString();
        }