C# Online Compiler | .NET Fiddle

using System;
					
public class Program
{
	public static void Main()
    {
        ProcessBusinessLogic bl = new ProcessBusinessLogic();
        bl.ProcessCompleted += bl_ProcessCompleted; // register with an event
        bl.StartProcess();
    }

    // event handler
    public static void bl_ProcessCompleted(object sender, ProcessEventArgs e)
    {
        Console.WriteLine("Process " + (e.IsSuccessful? "Completed Successfully": "failed"));
		Console.WriteLine("Completion Time: " + e.CompletionTime.ToLongDateString());
    }
}

public class ProcessEventArgs : EventArgs
{
	public bool IsSuccessful { get; set; }
	public DateTime CompletionTime { get; set; }

}

public class ProcessBusinessLogic
{
    public event EventHandler<ProcessEventArgs> ProcessCompleted; // event

    public void StartProcess()
    {
		var data = new ProcessEventArgs();
		
		try
		{
			Console.WriteLine("Process Started!");
			
			//uncomment following to see the result
			//throw new NullReferenceException();
			
        	// some process code here..
			
			data.IsSuccessful = true;
			data.CompletionTime = DateTime.Now;
        	OnProcessCompleted(data);
		}
		catch(Exception ex)
		{
			data.IsSuccessful = false;
			data.CompletionTime = DateTime.Now;
			OnProcessCompleted(data);
		}
    }


    protected virtual void OnProcessCompleted(ProcessEventArgs e)
    {
        ProcessCompleted?.Invoke(this, e);
    }
}

 
using System;
                    
public class Program
{
    public static void Main()
    {
        ProcessBusinessLogic bl = new ProcessBusinessLogic();
        bl.ProcessCompleted += bl_ProcessCompleted; // register with an event
        bl.StartProcess();
    }
​
    // event handler
    public static void bl_ProcessCompleted(object sender, ProcessEventArgs e)
    {
        Console.WriteLine("Process " + (e.IsSuccessful? "Completed Successfully": "failed"));
        Console.WriteLine("Completion Time: " + e.CompletionTime.ToLongDateString());
    }
}
​
public class ProcessEventArgs : EventArgs
{
    public bool IsSuccessful { get; set; }
    public DateTime CompletionTime { get; set; }
​