等待ThreadPool上的所有任务完成

Question

This might have a very simple answer, already posted here somewhere, but there is also a lot of old misleading information about threads.

My question is this: How do I prevent my Console from terminating before the background work is complete? Since the Task is created far down in the business layers of my program, I do not have access to it when the Console terminates (not like in this simple example). Is there some way of awaiting all Tasks that have been created within the context of my application?

public class Program
{
    private static void Main(string[] args)
    {
       DoBackgroundWork();
       System.Console.WriteLine("Doing something else during background work");

       // Wait for all created Tasks to complete before terminating
       ???
    }

    private static void DoBackgroundWork()
    {
        var task = Task.Run(() =>
        {
            System.Console.WriteLine("Starting background work");
            Thread.Sleep(10000);
            System.Console.WriteLine("Background work finished!");
        });
    }
}

Answer 1

Return the task so that you can wait on it.

private static void Main(string[] args)
{
    var task = DoBackgroundWork();
    System.Console.WriteLine("Doing something else during background work");

    // Wait for all created Tasks to complete before terminating
    task.Wait();
}

private static Task DoBackgroundWork()
{
    var task = Task.Run(() =>
    {
        System.Console.WriteLine("Starting background work");
        Thread.Sleep(1000);
        System.Console.WriteLine("Background work finished!");
    });

    return task;
}