C#调用timer.Elapsed时报错返回类型错误。

C#调用timer.Elapsed时报错返回类型错误。

请求IT界Big佬们提示！

static void Main(string[] args)
        {
            System.Timers.Timer timer = new System.Timers.Timer();
            timer.Enabled = true;
            timer.Interval = 6000;
            timer.Start();
            timer.Elapsed += new ElapsedEventHandler(r1);
            Console.ReadKey();
        }
        private static async Task r1(object source, ElapsedEventArgs e)
        {

            String Message = "";
            //调试SQL事件，输出SQL语句
            Chormadb.Aop.OnLogExecuting = (sql, pars) =>
            {
                Console.WriteLine("Sql语句：" + sql);
                Console.WriteLine(string.Join(",", pars?.Select(it => it.ParameterName + ":" + it.Value)));
            };
            Baizedb.Aop.OnLogExecuting = (sql, pars) =>
            {
                Console.WriteLine("Sql语句：" + sql);
                Console.WriteLine(string.Join(",", pars?.Select(it => it.ParameterName + ":" + it.Value)));
            };
            //查询Chroma数据生成list文件

            var list = await Chormadb.Queryable<LCR_REEL>()
                .Where(x => x.CreateUserID == "1223876")//string.IsNullOrEmpty(x.Remark1) == true
                .Take(10)
                .ToListAsync();
            #region//for循环插入数据到baize
            try
            {
                foreach (var item in list)
                {
                    //查询baize有没有
                    var has = await Baizedb.Queryable<MC_LCR_REEL>().Where(x => x.Reel_Id == item.Reel_Id).CountAsync();
                    if (has <= 0)
                    {
                        var InsertSN = new MC_LCR_REEL();
                        {
                            InsertSN.ID = Sys.Guid;
                            InsertSN.Reel_Id = item.Reel_Id;
                            InsertSN.Part_No = item.Part_No;
                            InsertSN.Result = item.Result;
                            InsertSN.Value = item.Value;
                            InsertSN.Unit = item.Unit;
                            InsertSN.Enabled = 1;
                            InsertSN.CreateDate = item.CreateDate;
                            InsertSN.CreateUserID = item.CreateUserID;
                            InsertSN.ModifyUserID = item.ModifyUserID;
                            InsertSN.ModifyDate = item.ModifyDate;
                        }
                        Baizedb.Insertable(InsertSN).ExecuteCommand();
                        Message = "successful";
                    }
                    else
                    {
                        Console.WriteLine($"{item.Reel_Id}已存在");
                    }
                }
            }
            catch (Exception ex)
            {
                Console.WriteLine("Exception Message: " + ex.Message);
                Message = ex.Message;
            };

            #endregion

            #region for循环，插入到Baize库后添加标识到Chroma库
            if (Message == "successful")
            {
                foreach (var item in list)
                {
                    var uptedateSN = new LCR_REEL();
                    {
                        uptedateSN.Remark1 = "Y";
                    }
                    Chormadb.Updateable<LCR_REEL>()
                        .SetColumns(it => it.Remark1 == "Y")
                        .Where(it => it.Reel_Id == item.Reel_Id)
                        .ExecuteCommand();
                }
            }
            #endregion
            Console.WriteLine($"执行完成");
            Console.ReadKey();

        }

static void Main(string[] args)
        {
            System.Timers.Timer timer = new System.Timers.Timer();
            timer.Enabled = true;
            timer.Interval = 6000;
            timer.Start();
            timer.Elapsed += OnTimedEvent;
            Console.ReadKey();
        }

        private static async void OnTimedEvent(Object source, System.Timers.ElapsedEventArgs e)
        {
            await r1();
        }

        private static async Task r1()
        {
 
            String Message = "";
            //调试SQL事件，输出SQL语句
            .....
        }