Handle and raising events in C#

Events

class Counter
{
    public event EventHandler ThresholdReached;

    protected virtual void OnThresholdReached(EventArgs e)
    {
        EventHandler handler = ThresholdReached;
        handler?.Invoke(this, e);
    }

    // provide remaining implementation for the class
}

Event data

public class ThresholdReachedEventArgs : EventArgs
{
    public int Threshold { get; set; }
    public DateTime TimeReached { get; set; }
}

Event handlers

class Program
{
    static void Main()
    {
        var c = new Counter();
        c.ThresholdReached += c_ThresholdReached;

        // provide remaining implementation for the class
    }

    static void c_ThresholdReached(object sender, EventArgs e)
    {
        Console.WriteLine("The threshold was reached.");
    }
}

References
https://docs.microsoft.com/en-us/dotnet/standard/events/
https://www.tutorialsteacher.com/csharp/csharp-event

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