Play with async calls

gistfile1.cs

using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Net.Http;
using System.Text;
using System.Threading.Tasks;

namespace AsyncTest
{
    class Program
    {
        static void Main(string[] args)
        {
            Console.WriteLine("Play with exception in asynchronous task");
            MainAsync().Wait();
            Console.WriteLine("Play with composing of asynchronous tasks");
            List<string> urls = new List<string>
            {
                "http://www.google.com",
                "http://www.altaine.com",
                "http://www.microsoft.com"
            };
            Task<string[]> getUrls = GetPages(urls);
            getUrls.Result.ToList().ForEach(p => Console.WriteLine("Page length: {0}", p.Length));
            Console.WriteLine("I'm done now!");
            Console.ReadLine();
        }

        static async Task<string[]> GetPages(List<string> urls)
        {
            var tasks = urls.Select(async url =>
                { 
                    using(var client = new HttpClient())
                    {
                        var res = await client.GetStringAsync(url);
                        Console.WriteLine("Downloading: {0}, Length: {1}",url, res.Length);
                        return res;
                    }
                }).ToList();
            return await Task.WhenAll(tasks);
        }

        static async Task MainAsync()
        {
            Console.WriteLine("MainAsync");
            Task<string> task = ReadFileAsync("unknown place");
            try
            {
                Console.WriteLine("MainAsync-try");
                string text = await task;
                Console.WriteLine("Text: {0}", text);
            }
            catch (Exception ex)
            {
                Console.WriteLine("Caught Exception: {0}", ex.Message);
            }
        }

        private static async Task<string> ReadFileAsync(string filename)
        {
            Console.WriteLine("ReadFileAsync");
            using(var reader = File.OpenText(filename))
            {
                return await reader.ReadToEndAsync();
            }
        }
    }
}