個推訊息推送主要步驟：1.獲取鑑權token 2.傳送推送訊息

1.獲取鑑權token(會過期，需要間隔時間獲取一次):
tokenUrl = "https://restapi.getui.com/v2/" + appId + "/auth";
        private string GetToken()
        {
            long nowTime ;    //當前的時間戳 毫秒級   
            string sign = appKey + nowTime + masterSecret;
            string sha256Sign = SHA256EncryptString(sign);  //
 
用sha256加密
            string postParam = "{\"sign\":\"" + sha256Sign + "\",\"timestamp\":\"" + nowTime + "\",\"appkey\":\""+ appKey + "\"}";   //json格式的post引數 appkey masterSecret appid 申請應用後會有

            return HttpRequestPost(tokenUrl, postParam);
        }

        private string HttpRequestPost(string
 
 Url, string Param)
        {
            string result = string.Empty;
            try
            {
                HttpWebRequest request = (HttpWebRequest)WebRequest.Create(Url);
                request.Timeout = Timeout;
                request.ContentType = "application/json;charset=utf-8";
                request.ReadWriteTimeout 
 
= Timeout;
                request.Proxy = null;
                request.ServicePoint.Expect100Continue = false;
                request.KeepAlive = false;
                request.ServicePoint.ConnectionLimit = 1000;    //物件最大連線數

                request.Method = "POST";

                byte[] data = Encoding.UTF8.GetBytes(Param);
                using (Stream requestStream = request.GetRequestStream())
                {
                    using (StreamWriter swrite = new StreamWriter(requestStream))
                    {
                        swrite.Write(data);
                    }
                }
                HttpWebResponse wbResponse = (HttpWebResponse)request.GetResponse();
                using (Stream responseStream = wbResponse.GetResponseStream())
                {
                    using (StreamReader sread = new StreamReader(responseStream))
                    {
                        result = sread.ReadToEnd();
                    }
                }
            }
            catch (Exception ex)
            {
                 Console.WriteLine("GeTuiMsgTask.HttpRequestPost post failed url={0} ex={1}", Url, ex);
            }
            return result;
        }

        private string SHA256EncryptString(string data)
        {
            byte[] bytes = Encoding.UTF8.GetBytes(data);
            byte[] hash = SHA256Managed.Create().ComputeHash(bytes);

            StringBuilder builder = new StringBuilder();
            for (int i = 0; i < hash.Length; i++)
            {
                builder.Append(hash[i].ToString("x2"));
            }
            return builder.ToString();
        }

2. 傳送推送訊息：必要引數
string cid 客戶端給過來的clientid（目標使用者）
string requestId 請求唯一標識號，10-32位之間；如果request_id重複，會導致訊息丟失
string title, 推送訊息標題
string content 推送內容

pushUrl = "https://restapi.getui.com/v2/" + appId + "/push/single/cid"; 推送url

 　　　　private void SendMsgNotification(object o)
        {
            MsgTaskItem item = (MsgTaskItem)o;
            string postParam = "{\"request_id\":\"" + item.RequestId + "\",\"audience\":{\"cid\":[\"" + item.Cid + "\"]}," +
                "\"push_message\":{\"notification\":{\"title\":\"" + item.Title + "\",\"body\":\"" + item.Content + "\",\"click_type\":\"none\",\"url\":\"\"}}}";
            string result = HttpRequestPost(pushUrl, postParam);   //返回結果成功也是json格式字串 
        }

更具體的檢視官方文件：https://docs.getui.com/getui/server/rest_v2/push/
線上http介面測試網站：https://www.sojson.com/http/test.html