Display time elapsed

Question

I need to display the elapsed time dynamically. My code will pop up a message based on an interval value.

public void button1_Click(object sender, EventArgs e)
{         


        

Answer 1

I wouldn't muck about with timers. I'd use Microsoft's Reactive Framework for this. Just NuGet "Rx-Winforms" to get the bits. Then you can do this:

Observable
    .Create(o =>
    {
        var now = DateTimeOffset.Now;
        var end = now.AddMinutes(15.0);
        return
            Observable
                .Interval(TimeSpan.FromSeconds(0.1))
                .TakeUntil(end)
                .Select(x => end.Subtract(DateTimeOffset.Now).ToString(@"mm\:ss"))
                .DistinctUntilChanged()
                .Subscribe(o);
    })
    .ObserveOn(this)
    .Subscribe(x => label1.Text = x);

This will automatically create a countdown timer that will update the text in label1 with the following values:

14:59 
14:58 
14:57 
14:56 
14:55 
14:54 
...
00:02
00:01
00:00

If you want to stop this before the timer runs out the Subscribe method returns an IDisposable that you can just call .Dispose().