How to get notification that a System.Threading.Tasks.Task has completed

Question

I am currently replacing some home baked task functionality with a new implementation using the new System.Threading.Tasks functionality found in .net 4.

I have a sl

Answer 1

I created a small example illustrating Jon Skeet's answer, which I'd like to share with you:

using System;
using System.Threading;
using System.Threading.Tasks;

public class Program
{
    static void Main(string[] args)
    {
        for (int cnt = 0; cnt < NumTasks; cnt++)
        {
            var task = new Task(DoSomething); // any other type than int is possible
            task.ContinueWith(t => Console.WriteLine($"Waited for {t.Result} milliseconds."));
            task.Start(); // fire and forget
        }

        PlayMelodyWhileTasksAreRunning();       
    }
    static int NumTasks => Environment.ProcessorCount;

    static int DoSomething()
    {
        int milliSeconds = random.Next(4000) + 1000;
        Console.WriteLine($"Waiting for {milliSeconds} milliseconds...");
        Thread.Sleep(milliSeconds);

        return milliSeconds; // make available to caller as t.Result
    }
    static Random random = new Random();

    static void PlayMelodyWhileTasksAreRunning()
    {
        Console.Beep(587, 200); // D
        Console.Beep(622, 200); // D#
        Console.Beep(659, 200); // E
        Console.Beep(1047, 400); // C
        Console.Beep(659, 200); // E
        Console.Beep(1047, 400); // C
        Console.Beep(659, 200); // E
        Console.Beep(1047, 1200); // C
        Console.Beep(1047, 200); // C
        Console.Beep(1175, 200); // D
        Console.Beep(1245, 200); // D#
        Console.Beep(1319, 200); // E
        Console.Beep(1047, 200); // C
        Console.Beep(1175, 200); // D
        Console.Beep(1319, 400); // E
        Console.Beep(988, 200); // H
        Console.Beep(1175, 400); // D
        Console.Beep(1047, 1600); // C
    }
}