C# Async

csharpasync.cs

using System;
using System.Linq;
using System.Net;
using System.Threading;
using System.Threading.Tasks;

namespace Blog_CSharpAsync
{
    class Program
    {
        static void Main(string[] args)
        {
            PrintBingHomePageHTMLAsync();

            Console.ReadKey();

            PrintFromOneToThenThenFromElevenToTwentyUsingTasks();

            Console.ReadKey();

            PrintFromOneToThenThenFromElevenToTwentyAsync();

            Console.ReadKey();
        }

        private static async void PrintBingHomePageHTMLAsync()
        {
            var bingHomePageHTML = await DownloadBingHomePageHTMLAsync();

            Console.WriteLine(bingHomePageHTML);
        }

        private static async Task<String> DownloadBingHomePageHTMLAsync()
        {
            var webClient = new WebClient();
            var html = await webClient.DownloadStringTaskAsync("http://www.bing.com");

            return html;
        }

        private static void PrintFromOneToThenThenFromElevenToTwentyUsingTasks()
        {
            var task = new Task(() =>
                                    Enumerable.Range(1, 10).ToList().ForEach(i =>
                                    {
                                        Thread.Sleep(10);
                                        Console.WriteLine(i);
                                    })
                                 );

            task.GetAwaiter().OnCompleted(() =>
                                            Enumerable.Range(11, 10).ToList().ForEach(i =>
                                            {
                                                Thread.Sleep(10);
                                                Console.WriteLine(i);
                                            })
                                          );
            task.Start();

            task.Wait();
        }

        private static async Task PrintFromOneToThenThenFromElevenToTwentyAsync()
        {
            await PrintFromOneToTenAsync();

            Enumerable.Range(11, 10).ToList().ForEach(i => Console.WriteLine(i));

            return;
        }

        private static async Task PrintFromOneToTenAsync()
        {
            var task = new Task(() =>
                        Enumerable.Range(1, 10).ToList().ForEach(i =>
                            {
                                Thread.Sleep(10);
                                Console.WriteLine(i);
                            })
                     );

            task.Start();

            await task;

            return;
        }
    }
}

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