// Wrap event invocations inside a protected virtual method
// to allow derived classes to override the event invocation behavior
protected virtual void OnThresholdReached(ThresholdReachedEventArgs e)
{
// Make a temporary copy of the event to avoid possibility of
// a race condition if the last subscriber unsubscribes
// immediately after the null check and before the event is raised.
EventHandler <ThresholdReachedEventArgs> thresholdReached = ThresholdReached;
// Event will be null if there are no subscribers, checking for null
// Call to raise the event.
thresholdReached?.Invoke(this, e);
}
public void Add(int x)
{
_total += x;
if (_total < Threshold)
{
return;
}
var args = new ThresholdReachedEventArgs(Threshold, DateTime.Now);
// Raising an event. You can also raise an event
// before you execute a block of code.
OnThresholdReached(args);
}
// Define what actions to take when the event is raised.
// This is EVENT HANDLER
private static void Counter_ThresholdReached(object sender, ThresholdReachedEventArgs e)
{
Console.WriteLine($"The threshold of {e.Threshold} is reached at {e.TimeReached:F}");
Environment.Exit(0);
}