AmazonCrawler.cs

using System;
using System.Net.Http;
using System.Threading;
using System.Threading.Tasks;

/* packages.config */
/*
<?xml version="1.0" encoding="utf-8"?>
<packages>
    <package id="HtmlAgilityPack" version="1.8.11" targetFramework="net472" />
    <package id="System.Buffers" version="4.5.0" targetFramework="net472" />
    <package id="System.Memory" version="4.5.1" targetFramework="net472" />
    <package id="System.Net.Http.WinHttpHandler" version="4.5.1" targetFramework="net472" />
    <package id="System.Numerics.Vectors" version="4.5.0" targetFramework="net472" />
    <package id="System.Runtime.CompilerServices.Unsafe" version="4.5.2" targetFramework="net472" />
</packages>
 */

namespace Amazon.ConsoleApp
{
    class Program
    {
        static void Main(string[] args)
        {
            using (HttpClient client = new HttpClient(new AmazonHttp2Crawler()))
            {
                client.BaseAddress = new Uri("https://www.amazon.com");
                //client.DefaultRequestHeaders.TryAddWithoutValidation("Accept", "text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8");
                //client.DefaultRequestHeaders.TryAddWithoutValidation("Accept-Encoding", "gzip, deflate, sdch, br");
                //client.DefaultRequestHeaders.TryAddWithoutValidation("Accept-Language", "en-US,en;q=0.8");
                //client.DefaultRequestHeaders.TryAddWithoutValidation("User-Agent", "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_10_5) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/51.0.2704.103 Safari/537.36");
                var getAsyncRequest = Task.Run(() => client.GetAsync("dp/B079K9BZKF"));
                getAsyncRequest.Wait();
                var getHttpResponse = getAsyncRequest.Result;
                var getResultContent = Task.Run(() => getHttpResponse.Content.ReadAsStringAsync());
                getResultContent.Wait();
                var htmlContent = getResultContent.Result;
                HtmlAgilityPack.HtmlDocument doc = new HtmlAgilityPack.HtmlDocument();
                doc.LoadHtml(htmlContent);
                var productName = doc.DocumentNode.SelectSingleNode("//*[@id='productTitle']").InnerText.Trim();
                var price = doc.DocumentNode.SelectSingleNode("//*[@id='priceblock_ourprice']").InnerText;
                Console.WriteLine($"{productName} - {price}");
                Console.ReadKey();
            }
        }
    }

    public class AmazonHttp2Crawler : WinHttpHandler
    {
        protected override Task<HttpResponseMessage> SendAsync(HttpRequestMessage request, CancellationToken cancellationToken)
        {
            //request.Version = new Version("2.0");

            /* Amazon, response'u gzip ile gonderdigi icin asagidaki satir ile gelen cevabi decompress etmek zorundayiz! */
            AutomaticDecompression = System.Net.DecompressionMethods.GZip | System.Net.DecompressionMethods.Deflate;
            return base.SendAsync(request, cancellationToken);
        }
    }
}