a thread doesn't work when I use ToListAsync method

Question

I have an EF Core program.

Code

class EagerLoading
{
    public async void load()
    {
        Console.WriteLine("a");
        var teams = await loadTeamsAsync();
        Console.WriteLine("c");
    }
    public async Task<List<Team>> loadTeamsAsync()
    {
        Console.WriteLine("b");
        using (var context = new SchoolContext())
        {
            return await context.teams.
                ToListAsync();
        }
    }
}
//Entry method
static void Main(string[] args)
{
    new EagerLoading().load();
}

Output

a
b

Expected

a
b
c

Question

where am I wrong? why the Console.WriteLine("c"); doesn't execute?

Answer 1

You will need to put a ReadKey or similar in the Main method to stop the application from exiting.

Load is an async void (which should be ringing alarm bells) and runs unobserved, in-turn there is a high probability of the application exiting before it finishes in the way you expect (or in this case writing to the console).

static void Main(string[] args)
{
    new EagerLoading().load();
    Console.ReadKey();
}

_{Note : You should only ever be using on async voids on event handlers (or constructs that logically represent event handlers), it's more-or-less the primary reason they exist.}