System.Timers.Timer How to get the time remaining until Elapse

Question

Using C#, how may I get the time remaining (before the elapse event will occur) from a System.Timers.Timer object?

In other words, let say I set the timer interval to 6 hours, but 3 hours later, I want to know how much time is remaining. How would I get the timer object to reveal this time remaining?

Answer 1

The built-in timer doesn't provide the time remaining until elapse. You'll need to create your own class which wraps a timer and exposes this info.

Something like this should work.

public class TimerPlus : IDisposable {     private readonly TimerCallback _realCallback;     private readonly Timer _timer;     private TimeSpan _period;     private DateTime _next;      public TimerPlus(TimerCallback callback, object state, TimeSpan dueTime, TimeSpan period)     {         _timer = new Timer(Callback, state, dueTime, period);         _realCallback = callback;         _period = period;         _next = DateTime.Now.Add(dueTime);     }      private void Callback(object state)     {         _next = DateTime.Now.Add(_period);         _realCallback(state);     }      public TimeSpan Period => _period;     public DateTime Next => _next;     public TimeSpan DueTime => _next - DateTime.Now;      public bool Change(TimeSpan dueTime, TimeSpan period)     {         _period = period;         _next = DateTime.Now.Add(dueTime);         return _timer.Change(dueTime, period);     }      public void Dispose() => _timer.Dispose(); } 

Answer 2

I am aware, that the topic is more than 3 years old. However I came across it while tackling exactly the same problem.

Inspired by Samuel Neff, I came up with a WinForms-less solution by extending the standard System.Timers.Timer class:

public class TimerPlus : System.Timers.Timer {     private DateTime m_dueTime;      public TimerPlus() : base() => this.Elapsed += this.ElapsedAction;      protected new void Dispose()     {         this.Elapsed -= this.ElapsedAction;         base.Dispose();     }      public double TimeLeft => (this.m_dueTime - DateTime.Now).TotalMilliseconds;     public new void Start()     {         this.m_dueTime = DateTime.Now.AddMilliseconds(this.Interval);         base.Start();     }      private void ElapsedAction(object sender, System.Timers.ElapsedEventArgs e)     {         if (this.AutoReset)             this.m_dueTime = DateTime.Now.AddMilliseconds(this.Interval);     } } 

I hope it helps.