设置系统时钟

 private DispatcherTimer _timer;


   private void SetTimeElaspInStatusBar()
        {
            try
            {
                
                _timer = new DispatcherTimer();
                _timer.Tick += (sender, e) =>
                {
                    DateTime dtNow = DateTime.Now;
                    TimeSpan interval = dtNow - _enterSystemTime;

                    this.barElapsedTime.Content = null;

                    #region

                    TimeZoneInfo currentTimeZone = TimeZoneUtil.GetLocalTimeZone();
                    if (currentTimeZone != null)
                    {
                        string str = currentTimeZone.Id;

                        this.barElapsedTime.Content += "     Local Time(" + str + " )"
                            + ": "
                            + dtNow.ToString("MM/dd/yyyy HH:mm:ss");

                        //DateTimeUtil.ConvertToUniversalTimeString(this._enterSystemTime, "MM/dd/yyyy HH:mm:ss");
                    }

                    //this.barElapsedTime.Content += "     UTC Time : "
                    //    + DateTimeUtil.ConvertToUniversalTimeString(dtNow, "MM/dd/yyyy HH:mm:ss");

                    DateTime? dtUTC =TimeZoneUtil.ConvertTimeToUTC(dtNow);
                 
                    if (dtUTC != null)
                    {
                        this.barElapsedTime.Content += "     UTC Time : "
                            +((DateTime)dtUTC).ToString("MM/dd/yyyy HH:mm:ss");
                    }


                    ////Convert To "Central America Standard Time"
                    //DateTime? dtUSCenter = TimeZoneUtil.ConvertFromUTC((DateTime)dtUTC, "Central America Standard Time");

                    //if (dtUSCenter != null)
                    //{

                    //    this.barElapsedTime.Content += "     UTC Time to  Central America Standard Time: "
                    //                               + ((DateTime)dtUSCenter).ToString("MM/dd/yyyy HH:mm:ss");
                    //}

                    #endregion

                    this.barElapsedTime.Content += "        Elapsed Time: " + (interval.Days > 0 ? interval.Days + " day(s) " : "") +
                       new DateTime(1900, 1, 1, interval.Hours, interval.Minutes, interval.Seconds).ToString("HH:mm:ss");

                    //
                    if (EventBinder.SystemTimeOutCheck.IsCheckTimeOut)
                    {
                        EventBinder.SystemTimeOutCheck.Check();
                    }
                   // SystemThreadStarter.StartGetUrlThread();
                };
                _timer.Interval = TimeSpan.FromSeconds(1);
                _timer.Start();
            }
            catch (Exception ex)
            {
                MessageBox.Show(ex.Message);
            }
        }