[HttpGet]

        public ApiActionResult OnceBackDemo()

        {

            var result = new ApiActionResult()

            {

                Success = false,

                Result = null,

                Message = "操作失败。"

            };

            System.Threading.ManualResetEvent mre = new System.Threading.ManualResetEvent(false);

            mre.Reset();

            Random rm = new Random();

            Action<Stopwatch> task = (sw) =>

            {

                sw.Start();

                int rm_val = rm.Next(1000);

                System.Threading.Thread.Sleep(rm_val);

            };

            var sw_out = new Stopwatch();

            task.BeginInvoke(sw_out, (ar) =>

            {

                task.EndInvoke(ar);

                mre.Set();

                sw_out.Stop();

                result.Success = true;

                result.Message = DateTime.Now + "->操作成功,耗时：" + sw_out.ElapsedMilliseconds.ToString()+"毫秒。";

            }, null);

            if (!mre.WaitOne(1500))

            {

                return result;

            }

            return result;

        }