How to add a timer to an app!

I have an app that I would like to update on an interval. I am looking for maybe some type of if statement or try - catch statement. I already have a foreach statement in the same class, but i dont think I can put in there? I would also like to set it up so that the user can change the refresh rate. Any help is appreciated. Thanks

Here is the method that I would like to put the timer in...

private void _UpdatePortStatus(string[] files)
{

 foreach (string file in files)

            {
            PortStatus ps = new PortStatus();
            ps.ReadXml(new StreamReader(file));



            if (!_dicPortStatus.ContainsKey(ps.General[0].Group))
            {
                _dicPortStatus.Add(ps.General[0].Group, ps);
            }

            PortStatus psOrig = _dicPortStatus[ps.General[0].Group];

            foreach (PortStatus.PortstatusRow psr in ps.Portstatus.Rows)
            {
                DataRow[] drs = psOrig.Portstatus.Select("PortNumber = '" + psr.PortNumber + "'");

                if (drs.Length == 1)
                {
                    DateTime curDt = DateTime.Parse(drs[0]["LastUpdateDateTimeUTC"].ToString());
                    DateTime newDt = psr.LastUpdateDateTimeUTC;

                    if (newDt > curDt)
                    {
                        drs[0]["LastUpdateDateTimeUTC"] = newDt;
                    }
                }
                else if (drs.Length == 0)
                {
          开发者_Python百科          psOrig.Portstatus.ImportRow(psr);
                }
                else
                {
                    throw new Exception("More than one of the same portnumber on PortStatus file: " + file);
                }
            }
        }
    }

Look at the System.Timer class. You basically set an interval (eg. 10000 milliseconds) and it will raise an event every time that interval time passes.

To allow the use to change the refresh rate, write a method that receives input from the user and use that to update the TimerInterval. Note that the TimerInterval is in miliseconds, so you may need to convert to that from whatever the user input.

So, from the example, the event will be raised every 10 seconds:

System.Timers.Timer aTimer = new System.Timers.Timer(10000); //10 seconds

// Hook up the Elapsed event for the timer.
aTimer.Elapsed += new ElapsedEventHandler(OnTimedEvent);
aTimer.Enabled = true; // Starts the Timer

// Specify what you want to happen when the Elapsed event is raised
private static void OnTimedEvent(object source, ElapsedEventArgs e)
{
    //Perform update
    _UpdatePortStatus(files);
}

UPDATE: In response to your posted code, it appears you simply want to call _UpdatePortStatus to update the port status at regular intervals (see the updated example above).

One important point you need to bear in mind though is that the Timer will run on a separate thread, and as such could raise the event again before it has finished running from the last time if it takes more than the interval time to run.

Use System.Timers.Timer, System.Threading.Timer or System.Windows.Forms.Timer ... depending on what exactly it is that you "would like to update on an interval."

See the following articles:

http://www.intellitechture.com/System-Windows-Forms-Timer-vs-System-Threading-Timer-vs-System-Timers-Timer/

http://www.yoda.arachsys.com/csharp/threads/timers.shtml

Your question is somewhat vague as there an many different methods of achieving what you want to do. However in the simplest terms you need to create a System.Threading.Timer that ticks on whatever frequency you define, for example:

private System.Threading.Timer myTimer;

private void StartTimer()
{
        myTimer = new System.Threading.Timer(TimerTick, null, 0, 5000);
}

private void TimerTick(object state)
{
    Console.WriteLine("Tick");
}

In this example the timer will 'tick' every 5 seconds and perform whatever functionality you code into the TimerTick method. If the user wants to change the frequency then you would destroy the current timer and initialise with the new frequency.

All this said, I must stress that this is the simplest of implementation and may not suit your needs.