using System;

using System.Threading.Tasks;

public class Program

{

    public static void Main()

    {

        var demo = new AsyncDemo();

        demo.Demo().Wait();

    }

}

​

public class AsyncDemo

{

    public async Task Demo() {

        var nothingResult = this.NothingAsync();

        Console.WriteLine("nothingResult = {0}", nothingResult);

        Console.WriteLine("about to await nothingResult: {0}");

        await nothingResult;

        Console.WriteLine("done!");

        var waitResult = this.WaitAsync();

        Console.WriteLine("waitResult = {0}", waitResult);

        Console.WriteLine("about to await waitResult");

        await waitResult;

        Console.WriteLine("done!");

        var notReallyAsyncResult = this.NotReallyAsync();

        Console.WriteLine("notReallyAsyncResult = {0}", notReallyAsyncResult);

        Console.WriteLine("about to await notReallyAsyncResult");

        await waitResult;

        Console.WriteLine("done!");

    }

    public async Task NothingAsync()

    {

        // This will produce an analyzer warning but is still a valid async method.

    }

    public async Task WaitAsync()

    {

        await Task.Delay(1000);

    }

    public Task NotReallyAsync()

    {

        return Task.CompletedTask;

    }

}