.net core发送钉钉消息_消息加签模式

这是一篇纯记录代码文章，完整运行需要自己调整：

钉钉发送消息后台进行了改版，这里介绍加签模式的代码：

/// <summary>
        /// 发送钉钉消息内容
        /// </summary>
        /// <param name="groupName"></param>
        /// <param name="content"></param>
        /// <returns></returns>
        public async Task SendDingdingMessage(string content)
        {
            return;//去掉钉钉消息通知

            string requestHost = this._httpContextAccessor.HttpContext.Request.Host.Value;
            //测试和仿真环境发钉钉提示消息
            if (requestHost.Contains("meshop.net") || requestHost.Contains("runshopstore.com"))
            {
                string sign = null;

                TimeSpan ts = DateTime.UtcNow - new DateTime(1970, 1, 1, 0, 0, 0, 0);
                string timeStamp = Convert.ToInt64(ts.TotalMilliseconds).ToString();

                var encoding = new UTF8Encoding();
                byte[] signBytes = encoding.GetBytes($"{timeStamp}
{this._dingDingGroup.Secret}");
                byte[] secretByte = encoding.GetBytes(this._dingDingGroup.Secret);
                using (var hmacsha256 = new HMACSHA256(secretByte))
                {
                    byte[] hashmessage = hmacsha256.ComputeHash(signBytes);
                    sign = HttpUtility.UrlEncode(Convert.ToBase64String(hashmessage));
                }

                string messageUrl = $"{this._dingDingGroup.WebHookUrl}&timestamp={timeStamp}&sign={sign}";
                List<string> atPhoneList = null;
                if (!string.IsNullOrEmpty(this._dingDingGroup.AtPhones))
                {
                    atPhoneList = this._dingDingGroup.AtPhones.Split(',').ToList();
                    atPhoneList.RemoveAll(m => string.IsNullOrEmpty(m));
                }
                DingDingText dingDingText = new DingDingText
                {
                    msgtype = "text",
                    text = new DingDingText.textObj
                    {
                        content = $"{CONST.HOST_ADMIN}_{content}"
                    },
                    at = new DingDingText.atObj
                    {
                        isAtAll = false,
                        atMobiles = atPhoneList
                    }
                };

                HttpClient httpClient = this._httpClientFactory.CreateClient();
                await httpClient.Post(messageUrl, JsonHelper.ConvertJsonToStr(dingDingText), "application/json");
            }
        }