How to prevent my method launches every loop 10 seconds earlier - forms

Question

I want my other method launches precice 1:50 (10 seconds before ending) The problem is, it launches 10secondes too early every loop. It looks like
1 st loop
1:50 Method launches - correct
2 nd loop
3:40 Method launches - incorrect (10 seconds shorter)
3 rd loop
5:30 Method launches - incorrect (10 seconds shorter)
4 th loop
7:20 Method launches - incorrect (10 seconds shorter)
......
I want every 110 seconds my method launches precisely every 110 seconds.
the code:
private void OnTimerElapsed(object sender, ElapsedEventArgs e)
{
Application.Current.Dispatcher.BeginInvokeOnMainThread(() =>
{
MainTimer.Text = stopwatch.Elapsed.ToString(#"hh\:mm\:ss");
double counter = stopwatch.Elapsed.TotalSeconds;
Tasklabel.Text = counter.ToString(); // tried to look what's going on
if (((int)counter % 120 == 0 && (int)counter != 0))
{
Value = false;
stopwatch.Stop();
timer.Stop();
// do sth
}
// I tried
//counter2 += 10;
// also tried to assign another variable // double counter2 = stopwatch.Elapsed.TotalSeconds;
if (((int)counter2 % 110 == 0 && (int)counter2 != 0))
{
// do sth
}
});
}
How to write it properly

Answer 1

You could make a small change to the code.
private void OnTimerElapsed(object sender, ElapsedEventArgs e)
{
Application.Current.Dispatcher.BeginInvokeOnMainThread(() =>
{
MainTimer.Text = stopwatch.Elapsed.ToString(#"hh\:mm\:ss");
double counter = stopwatch.Elapsed.TotalSeconds;
if ((((int)counter + 10) % 120 == 0 && (int)counter != 0)) // make changes here
{
//make a stop at 1:50, 3:50, 5:50...
Value = false;
timer.Stop();
stopwatch.Stop();
counter = 0;
// do sth
Console.WriteLine("TIMER Close==============");
}
});
}
Hope it works for you.