How to stop a Timer object after a set interval of time?

Question

I've assigned a string value from a text box to a date time variable.It's purpose is to serve as a flag to tell myTimer object to stop when it has reached the the time stored in workDt,(the date time variable).

The current implementation I have tried is the following, where I set up an if..else statement to check if the timer's current time is equal to what was entered in the text box but it doesn't trigger the timer to stop.

I set a break point on the 'if' statement and the time value is being stored in the workDt but isn't triggering the timer to stop.

Can anyone see a flaw in my implementation or offer any advice on an alternative solution?

private void startBtn_Tap(object sender, System.Windows.Input.GestureEventArgs e)
        {


            string wrkString;
            string rstString; 


            //Assign text box time string to string variables.
            wrkString = wrkTbx.Text;
            rstString = restTbx.Text;


            //Assign text box string value to a date time variable.

            DateTime workDt = DateTime.ParseExact(wrkString.Replace(": ", ":").Replace(" :", ":"), "HH:mm:ss:fff", CultureInfo.InvariantCulture);
            DateTime restDt = DateTime.ParseExact(rstString.Replace(": ", ":").Replace(" :", ":"), "HH:mm:ss:fff", CultureInfo.InvariantCulture);


            StopGoCvs.Background = new SolidColorBrush(Colors.Green);
            hornElmt.Play();
            //    // set up the timer
            myTimer = new DispatcherTimer();
            myTimer.Interval = new TimeSpan(0, 0, 0, 0, 1);
            myTimer.Tick += myTimer_Tick;

            //tell timer to stop when it has reached the allocated work time.
            if(myTimer.Interval != workDt.TimeOfDay)
            {
                // start both timers
                myTimer.Start();
                myStopwatch.Start();

            }
            else
            {
                myTimer.Stop();
                myStopwatch.Stop();

            }



        }

Answer 1

使计时器对象成为全局对象，以便类中的所有方法或事件都可以访问，然后启动计时器给每次到达的时间都分配一个事件，然后在该事件上有条件地检查时间是否达到您的预期时间，然后停止计时器。

Answer 2

setting the Interval to: myTimer.Interval = new TimeSpan(0, 0, 0, 0, 1); means you set a 1ms Interval thus making in it impossible for the condition:

myTimer.Interval == workDt.TimeOfDay

ever to be met

What you are looking for is more of a StopWatch rather than a timer.