// sync Members to  API
        public async System.Threading.Tasks.Task <ActionResult> SynMember(string id)
        {
            // SYNC MEMBERS (can` string id cua course)
            // START
            Session["MaKH"] = id;
            var item = db.ThamDus.Where(x => x.MaKH == id).ToList();

            string lecid = (string)Session["MaGV"];
            string sec   = (string)Session["secret"];

            ThamDu Member = new ThamDu();

            string[] sID = new string[item.Count()];
            int      i   = 0;

            foreach (var items in item)
            {
                sID[i] = items.MSSV.ToString();
                i++;
            }

            Members mem = new Members();

            mem.course  = id;
            mem.members = sID;

            string json   = JsonConvert.SerializeObject(mem);
            var    values = new Dictionary <string, string>
            {
                { "uid", lecid },
                { "secret", sec },
                { "data", json }
            };

            var content  = new FormUrlEncodedContent(values);
            var response = await client.PostAsync("https://entool.azurewebsites.net/SEP21/SyncMembers", content);

            var responseString = await response.Content.ReadAsStringAsync();

            GetResponeMessage ResponeMessage = JsonConvert.DeserializeObject <GetResponeMessage>(responseString);

            Session["SynMessage"] = ResponeMessage.message.ToString();
            // END

            return(RedirectToAction("ListStudent", "Course", new { id = (string)Session["MaKH"] }));
        }
        //Sync Attendance to API

        public async System.Threading.Tasks.Task <ActionResult> syncAttendanceAsync()
        {
            HttpClient client = new HttpClient();

            string id    = (string)Session["MaKH"];
            string lecid = (string)Session["MaGV"];
            string sec   = (string)Session["secret"];

            var value = new
            {
                course   = id,
                sessions = db.BuoiHocs.Where(x => x.MaKH == id).AsEnumerable().Select(b => new
                {
                    id   = b.Buoi_thu,
                    date = DateTime.Parse(b.NgayHoc.ToString()).ToString("yyyy-MM-ddThh:mm:ss"),
                    info = string.Empty
                }).ToArray(),
                attendance = db.DiemDanhs.AsEnumerable().Where(x => x.BuoiHoc.MaKH == id).Select(m => new
                {
                    student   = m.MSSV,
                    checklist = db.DiemDanhs.Where(x => x.status == true && x.BuoiHoc.MaKH == id && x.MSSV == m.MSSV).Select(z => z.BuoiHoc.Buoi_thu).ToArray(),
                    info      = string.Empty
                })
            };
            var json = JsonConvert.SerializeObject(value);

            var values = new Dictionary <string, string>
            {
                { "uid", lecid },
                { "secret", sec },
                { "data", json }
            };

            var content  = new FormUrlEncodedContent(values);
            var response = await client.PostAsync("https://entool.azurewebsites.net/SEP21/SyncAttendance", content);

            var responseString = await response.Content.ReadAsStringAsync();

            GetResponeMessage ResponeMessage = JsonConvert.DeserializeObject <GetResponeMessage>(responseString);

            //	Session["SynMessage"] = ResponeMessage.message.ToString();

            return(RedirectToAction("ListDiemDanh", new { id = Session["BH"] }));
        }