How to await on async delegate

Question

In one of MVA videos i saw next construction:

static void Main(string[] args)
{
    Action testAction = async () =>
    {
        Console.WriteLine(\"In\");
          


        

Answer 1

In order for something to be awaited, it has to be awaitable. As void is not so, you cannot await on any Action delegate.

An awaitable is any type that implements a GetAwaiter method, which returns a type that implements either INotifyCompletion or ICriticalNotifyCompletion, like Task and Task, for example.

If you want to wait on a delegate, use Func, which is an equivalent to a named method with the following signature:

public Task Func()

So, in order to await, change your method to:

static void Main(string[] args)
{
    Func testFunc = async () =>
    {
        Console.WriteLine("In");
        await Task.Delay(100);
        Console.WriteLine("First delay");
        await Task.Delay(100);
        Console.WriteLine("Second delay");
    };
}

And now you can await it:

await testFunc();