using System;

using System.IO;

using System.Text;

using System.Threading;

using System.Threading.Tasks;

​

public class Program

{

  public static void Main(string[] args)

  {

    File.WriteAllText("test.txt", "read from file");

    Read(File.OpenText("test.txt")).Wait();     

    Read(new StreamReader(File.Create("testTwo.txt"))).Wait();

    Read(new StreamReader(new MemoryStream(Encoding.UTF8.GetBytes("read from another string")))).Wait();

    Console.WriteLine("{0}: {1}", Thread.CurrentThread.ManagedThreadId, "main thread");

  }

  static async Task Read(StreamReader sr)

  {

    var s = await sr.ReadToEndAsync();

    Console.WriteLine("{0}: {1}", Thread.CurrentThread.ManagedThreadId, string.IsNullOrEmpty(s) ? "nothing written to the file" : s);

  }

}