Can I use the new async/await method with this code

Question

I recently installed VS2012 and I'm reading on the new async modifier and how to use it for async programming.

Now, I'ts pretty easy to use with built-in framework function like in System.IO or in web service calls but I'm trying to use with my own function. I made a small console application, basically the async task is a random number that will be generated in loop until it equals 0 and I want to display loading message in the mean-time. Here's the code that I have done:

    private static void Main(string[] args)
    {
        var rnd = new Random();
        var factory = new TaskFactory();

        var task = GetRandomNumber(rnd);
        while(!task.IsCompleted){
        System.Console.Write("Loading .");
        System.Console.Write(".");
        System.Console.Write("./n");
        }
    }

    private static async Task GetRandomNumber(Random rnd)
    {
        await new Task(delegate
            {
                while (rnd.Next() != 0)
                {
                }
            });
    }

It's obvious that I'm pretty lost on how to do that here I just keep coding it like if I was multi, is it possible to implement this behavior with the async/await pattern? How?

Answer 1

async does not necessarily imply "multithreaded". You can use Task.Run to spin a new background task that you can await .

private static void Main(string[] args)
{
    var rnd = new Random();
    var task = GetRandomNumber(rnd);
    while(!task.IsCompleted){
    System.Console.Write("Loading .");
    System.Console.Write(".");
    System.Console.Write("./n");
    }
}

private static Task GetRandomNumber(Random rnd)
{
    return Task.Run(() =>
        {
            while (rnd.Next() != 0)
            {
            }
        });
}

Though I would probably do it like this:

private static void Main(string[] args)
{
  MainAsync().Wait();
}

private static async Task MainAsync()
{
  var rnd = new Random();
  var randomTask = GetRandomNumber(rnd);
  System.Console.Write("Loading .");
  while (await Task.WhenAny(randomTask, Task.Delay(500)) != randomTask)
  {
    System.Console.Write(".");
  }
  System.Console.WriteLine();
}

private static Task GetRandomNumber(Random rnd)
{
  return Task.Run(() =>
  {
    while (rnd.Next() != 0)
    {
    }
  });
}